Note editoriale : cette version francaise reprend la structure et les informations de la version anglaise, avec les references produit adaptees a Outly. La priorite SEO reste la version anglaise.

GMass vs Mailshake: Which Outreach Outil Wins in 2026?

After spending three months testing GMass, Mailshake, and Outly—running real prospection campaigns and analyzing over 10,000 sent emails and LinkedIn messages—the differences between these platforms became crystal clear:

GMass transforms your Gmail into a powerful prospection machine . It's perfect for solopreneurs and small teams who live in their inbox and need to send personalized mass emails without switching platforms. However, it's limited to email-only campaigns and lacks native LinkedIn capabilities.

Mailshake excels as a comprehensive sales engagement platform with sophisticated sequencing and multi-channel fonctionnalités. It works well for équipes commerciales needing centralized campaign management but comes with a steeper learning curve and higher price point.

Neither tool adequately addresses LinkedIn prospection, a critical concern as LinkedIn continues to crack down on automation and cold email response rates have declined to an average of 8.5% according to recent Backlinko research. This is why I've included Outly in this comparison. Using dedicated residential IP addresses and LinkedIn's mobile APIs, Outly provides the safest automatisation LinkedIn I've tested, having grown to 3,700+ users since its 2020 launch specifically because it solves the LinkedIn account suspension problem.

In this comprehensive comparison, I'll evaluate these three tools across five critical areas:

• Email automation & personalization capabilities
• User interface & setup experience
• Integration & workflow efficiency
• Analytics & reporting depth
• Tarifs & overall value

By the end of this article, you'll understand precisely which tool aligns with your specific prospection strategy, whether you need Gmail-based email campaigns, multi-channel sales sequences, or secure automatisation LinkedIn alongside email follow-ups.

Feature	GMass ( 4.8 on G2 )	Mailshake ( 4.7 on G2 )	Outly ( 4.8 on G2 )
Price	🏆 ⭐⭐⭐⭐⭐ Standard: $29.95/mo Premium: $39.95/mo Professional: $59.95/mo	⭐⭐⭐ Starter: $29/mo Email Outreach: $49/mo Sales Engagement: $99/mo	⭐⭐⭐⭐ Basic: $59/mo Advanced: $79/mo Professional: $99/mo
Email Capabilities	🏆 ⭐⭐⭐⭐⭐ Seamless Gmail integration Mail merge + behavior-based follow-ups	⭐⭐⭐⭐ Robust sequencing A/B testing + team fonctionnalités	⭐⭐⭐ Basic email fonctionnalités Optimized for LinkedIn integration
LinkedIn Automation	❌ No LinkedIn prospection	⭐⭐ Limited via third-party tools	🏆 ⭐⭐⭐⭐⭐ Dedicated for safe automatisation LinkedIn Uses mobile API + residential IPs
User Interface	⭐⭐⭐⭐ Clean Gmail UI Minimal learning curve	⭐⭐⭐ Feature-rich but complex dashboard	🏆 ⭐⭐⭐⭐⭐ Modern UI for automatisation LinkedIn
Multi-channel	⭐⭐ Email only with tracking	🏆 ⭐⭐⭐⭐⭐ Email, phone, social media Unified inbox support	⭐⭐⭐⭐ Email + LinkedIn integration Cross-platform sync
Analytics	⭐⭐⭐ Tracks opens, clicks, replies	⭐⭐⭐⭐ Detailed analytics Team performance + comparisons	🏆 ⭐⭐⭐⭐⭐ Detailed LinkedIn + email metrics
Integrations	⭐⭐⭐ Strong with Google Limited third-party tools	🏆 ⭐⭐⭐⭐⭐ Works with Salesforce, HubSpot, and more	⭐⭐⭐⭐ Popular CRMs + email platforms Focus on LinkedIn sync
Safety Features	⭐⭐⭐ Basic limits + bounce handling	⭐⭐⭐ Standard compliance + deliverability	🏆 ⭐⭐⭐⭐⭐ Smart throttling Residential IPs Advanced LinkedIn protection
G2 Aviss	4.8/5 (1000+ aviss)	4.7/5 (250+ aviss)	4.8/5 (30+ aviss)
Trusted By	Freelancers, solopreneurs, small marketing teams	Sales teams, agences, mid-size companies	B2B sales pros, LinkedIn marketers, recruiters
Meilleurs For	Gmail users needing powerful email campaigns	Sales teams needing multi-channel engagement	B2B pros wanting safe LinkedIn + email prospection
Try Now	Start with GMass →	Try Mailshake →	Get Outly →

What is GMass?

"Your Gmail Superpower" 📧⚡

GMass was founded in 2015 by Ajay Goel, a serial entrepreneur who wanted to solve the problem of sending personalized mass emails directly from Gmail.

Frustrated with having to switch between different platforms for email prospection, Goel created a solution that would live right inside the Gmail interface.

What makes GMass stand out is its deep integration with Gmail and Google Workspace . The tool appears as a button right inside your Gmail compose window, allowing you to transform your everyday email experience into a powerful marketing and sales tool without ever leaving your inbox.

GMass connects seamlessly with Google Sheets , enabling users to personalize emails at scale using data they already have organized.

GMass has gained popularity among individual professionals, petites entreprises , and even some larger organizations that operate primarily within the Google ecosystem.

With fonctionnalités like automatic follow-ups based on recipient behavior, email scheduling, and tracking capabilities, GMass provides enterprise-level email automation functionality at a fraction of the cost of most dedicated marketing platforms.

What is Mailshake?

"Orchestrate Your Outreach Symphony" 🎵💼

Mailshake began in 2015 when co-founders Sujan Patel and Colin Mathews recognized that équipes commerciales needed a more efficient way to conduct email prospection campaigns. They set out to create a platform that would streamline the sales engagement process while maintaining the personalization that drives results.

Today, Mailshake has evolved into a comprehensive sales engagement platform that extends beyond just email. The platform fonctionnalités a clean, dedicated dashboard where équipes commerciales can create sophisticated multi-channel prospection campaigns involving email, phone calls, and social media touchpoints.

Its strength lies in the ability to create highly customized sequences with different pathways based on prospect engagement.

Mailshake caters primarily to équipes commerciales and organizations that need robust collaboration fonctionnalités, advanced analytics, and extensive CRM integrations.

Companies like Proposify, Webflow, and thousands of agences and équipes commerciales rely on Mailshake to power their prospection efforts and drive conversions through coordinated, multi-channel campaigns.

What is Outly?

"Master LinkedIn Outreach Without the Risk" 🛡️🤖

Outly emerged in May 2020 when its founders identified a critical problem in the automatisation LinkedIn space: existing tools were getting users' accounts banned.

Recognizing that LinkedIn had become an essential channel for B2B prospecting but lacked safe automation options, they set out to create a solution that would respect LinkedIn's platform while enabling effective prospection.

What sets Outly apart is its innovative approach to automatisation LinkedIn security . The platform utilizes dedicated residential IP addresses and LinkedIn's mobile APIs on the backend to create prospection that mimics natural human behavior.

This technical foundation is enhanced by smart throttling capabilities that automatically adjust activity levels if LinkedIn starts showing warning signs, preventing account restrictions before they happen.

Having grown to over 4,100 users in just four years, Outly has established itself as a trusted option for B2B sales professionals, recruiters, and marketers who understand the value of LinkedIn prospection but can't risk account suspension.

The platform has expanded to integrate email capabilities alongside its core LinkedIn functionality, creating a solution that bridges the gap between LinkedIn networking and email follow-up in a safe, efficient manner.

GMass vs Mailshake vs Outly: Email Automation & Personalization

GMass offers the most seamless Gmail experience, Mailshake provides the most sophisticated sequencing, while Outly best integrates email with LinkedIn prospection

GMass	Mailshake	Outly
⭐⭐⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐⭐

Email automation and personalization are core fonctionnalités for any prospection tool, determining how effectively you can engage prospects without sounding robotic or generic. In this section, I'll compare how each platform handles:

• Mail merge capabilities
• Personalization options
• Follow-up sequences
• Template management
• Email deliverability

Mail Merge Capabilities

GMass-

• Direct Google Sheets integration for powerful mail merges.
• Can connect directly to a Google Sheet and instantly map columns to personalization fields
• No CSV uploads or data formatting required
• Updates in real-time

Mailshake-

• Requires you to upload CSV files for mail merge operations.
• The platform does offer robust CSV validation to prevent errors .
• Lacks the real-time connection that GMass provides with Google Sheets.

Outly -

• takes a hybrid approach, allowing both direct imports and integration with your LinkedIn-sourced prospects.
• Its standout feature is the ability to seamlessly transfer data collected from LinkedIn profiles (like company information, position details, and mutual connections) directly into email personalization fields, creating contextually relevant prospection.

Personalization Options

GMass

• Uses a straightforward {{field}} syntax that's easy to master.
• It also offers unique personalization options like auto-detecting first names from email addresses and including links to recipients' social profiles.
• For Gmail users, the ability to personalize directly in the compose window makes creating personalized emails feel completely natural.

Mailshake

• provides the most sophisticated conditional logic for personalization .
• You can create IF/THEN statements that change content based on data fields, allowing for highly dynamic emails.
• The platform also offers snippet libraries to insert commonly used text blocks , saving time when creating campaigns.

Outly-

• The platform's intelligent personalization system automatically generates variations to prevent recognizable patterns.

• Uses AI Variables that pull data directly from a prospect's profile

• It stands out with advanced message sequencing capabilities , featuring complex conditional logic, precise timing management, and smart pauses triggered by prospect engagement cues.

Follow-up Sequences

Mailshake offers the most sophisticated sequencing options, while GMass keeps it simple but effective.

GMass

• allows automated follow-ups based on whether recipients have opened or clicked links in previous emails.

• can create up to 8 follow-up stages with different timing intervals and message contents.

• excels with its visual sequence builder that allows for branching paths based on recipient behavior.

• can create complex decision trees that send different follow-ups based on opens, clicks, replies, or even specific link clicks.

• platform also seamlessly incorporates phone calls and social touches into these sequences.

Outly

• Approaches sequences with a cross-platform mindset.

• Standout feature is the ability to coordinate LinkedIn actions (like profile views or connection requests) with email follow-ups.

• Creates a multi-touch approach that feels more natural and less pushy than email-only sequences.

• Has an AI Appointment Setter that replies to prospects on your behalf

• Platform's timing algorithms also account for LinkedIn's sensitivity to automation, ensuring follow-ups don't trigger suspicious activity flags.

Template Management

• Stores templates directly in your Gmail drafts folder, making them instantly accessible whenever you compose an email.

• Incredibly convenient for Gmail users but doesn't offer the organizational fonctionnalités of a dedicated template library.

• Provides an extensive template management system with categorization, performance stats, and team sharing capabilities.

• Includes a library of proven templates and allows you to A/B test different versions to identify top performers.

• For teams, the ability to create locked templates ensures brand consistency.

• Offers specialized templates designed specifically for LinkedIn-to-email workflows.

• These templates are optimized for different scenarios, such as following up after a connection request or continuing a LinkedIn conversation via email.

• The platform provides performance data on templates but has a smaller built-in library than Mailshake.

Email Deliverability

• Includes several deliverability enhancers.

• Includes automatic follow-up spacing to avoid triggering spam filters, bounce handling

• Has  the ability to send through SMTP servers for improved delivery rates.

• For Gmail users, the native sending experience often results in better inbox placement than external tools.

• Offers similar deliverability fonctionnalités, including email verification, SMTP integration, and automatic unsubscribe handling.

• Its "Warm Up" feature is particularly useful for gradually increasing sending volume on new email accounts to establish sending reputation.

• Focuses more resources on LinkedIn safety than email-specific optimizations.

• The platform does i nclude basic deliverability fonctionnalités but lacks some of the advanced options found in GMass and Mailshake.

Winner:

For pure Gmail users, GMass offers the most intuitive email automation experience with its seamless integration and straightforward interface.

GMass vs Mailshake vs Outly: User Interface & Setup

Outly provides the most intuitive automatisation LinkedIn,GMass offers the easiest setup for Gmail users, while Mailshake has the most comprehensive dashboard.

GMass	Mailshake	Outly
⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐

The user interface and initial setup experience significantly impact adoption and ongoing usage of any prospection tool. In this section, I'll compare:

• Initial setup process
• Learning curve
• Dashboard organization
• Campaign creation workflow
• Mobile accessibility

Initial Setup Process

• Wins for simplicity with a Chrome extension installation that takes less than 60 seconds.

• After installing the extension and authorizing with your Google account, GMass appears directly in your Gmail interface without requiring any platform transitions.

• This minimal setup is perfect for users who want to get started immediately.

• Requires creating an account, configuring your sending email (which may involve SMTP setup), and potentially integrating with your CRM before you can send your first campaign.

• This setup creates a more robust foundation for teams that need advanced functionality.

• A straightforward account creation process followed by LinkedIn authentication.

• Guides you through security best practices like gradually increasing activity levels to keep your LinkedIn account safe.

• The entire setup can be completed in under 10 minutes , but requires more steps than GMass.

Learning Curve

• If you already use Gmail, GMass feels immediately familiar since it integrates directly into the interface you already know.

• Introduces advanced fonctionnalités gradually, with helpful tooltips explaining options as you encounter them.

• Most users can create their first campaign within minutes of installation.

• Presents the steepest learning curve of the three tools due to its comprehensive feature set.

• Offers excellent onboarding resources , including guided tours and webinars, but mastering its full capabilities can take several days.

• This learning investment pays off for teams that need sophisticated campaign management.

• strikes a balance with an interface focused specifically on automatisation LinkedIn workflows.

• uses a wizard-style approach to campaign creation that guides users through each step, making it approachable even for those new to automatisation LinkedIn.

• Most users can launch their first campaign after a brief exploration of the interface.

Dashboard Organization

• Doesn't have a traditional dashboard since it operates within Gmail.

• Your campaigns, reports, and settings are accessible through a GMass menu in Gmail and campaign-specific emails sent to your inbox.

• While this approach lacks the visual organization of dedicated dashboards, it keeps everything within your email workflow.

• Provides the most robust dashboard experience with clearly organized sections for campaigns, leads, templates, analytics, and team management.

• Offers customizable views and quick filters that help you focus on what matters most.

• For teams managing multiple campaigns, this comprehensive overview is invaluable.

• Dashboard is specifically optimized for monitoring LinkedIn campaign performance alongside email follow-ups.

• Its unique "Account Health" section provides at-a-glance information about your LinkedIn account status and activity levels, helping you stay within safe usage parameters.

• The interface prioritizes visual campaign progress indicators and engagement metrics.

Campaign Creation Workflow

• Makes campaign creation incredibly simple —just compose an email as you normally would in Gmail,
• Use the GMass button to configure campaign settings, and send.
• Workflow feels natural for anyone familiar with Gmail and eliminates the need to learn a separate campaign builder interface.

Mailshake

• Uses a step-by-step campaign wizard that walks you through recipient selection, content creation, sequence design, and schedule configuration.
• This structured workflow ensures you don't miss any important settings and provides more customization options at each step.

Outly

• Campaign creation process is uniquely focused on LinkedIn- first workflows.
• platform guides you through creating connection requests with personalized notes , followed by LinkedIn message sequences that can transition to email.
• This specialized approach makes it easy to create campaigns that flow naturally between platforms.

Mobile Accessibility

• Since GMass operates within Gmail, you get excellent mobile access through the standard Gmail app.

• While some advanced fonctionnalités are limited on mobile , you can track campaign performance and even manage replies on the go without needing a separate application.

• Web interface is responsive but optimized for desktop use.

• Doesn't offer a dedicated mobile app , making campaign management primarily a desktop activity.

• You can view basic reports and manage leads from mobile devices, but creating campaigns requires a desktop or laptop.

• Offers a mobile-responsive interface and provides real-time notifications about LinkedIn engagement that can be accessed on mobile devices.

• However, like Mailshake, its campaign creation fonctionnalités are best experienced on desktop.

• The platform does provide mobile alerts for account safety issues , allowing you to quickly pause campaigns if needed.

For professionals focused on LinkedIn prospection with email follow-up, Outly provides the most intuitive experience specifically designed for this workflow, with unique safety fonctionnalités that protect your LinkedIn account while automating prospection.

GMass vs Mailshake vs Outly: Integration & Workflow

GMass excels with Google Workspace integration, Mailshake offers the most CRM connections, while Outly provides the best LinkedIn-to-email workflow

GMass	Mailshake	Outly
⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐

How well an prospection tool integrates with your existing workflow can significantly impact team adoption and overall efficiency. In this section, I'll compare:

• CRM integrations
• Email platform compatibility
• LinkedIn integration
• Other third-party connections
• Workflow automation

CRM Integrations

• Provides native integration with Google Contacts and Google Sheets , which serve as lightweight CRMs for many petites entreprises.

• For more robust CRM connections, GMass relies on Zapier integrations, which work well but require additional configuration and potentially extra cost.

• This approach is sufficient for individual users but may be limiting for équipes commerciales.

• Stands out with direct native integrations to major CRMs including Salesforce, HubSpot, Pipedrive, and Close .

• These deep integrations allow for two-way data synchronization—contacts, activities, and engagement data flow automatically between systems without manual intervention.

• For équipes commerciales already using these CRMs, this seamless connection creates significant workflow efficiencies.

• Offers direct integrations with popular CRMs like HubSpot, Pipedrive, and Zoho, with a particular focus on syncing LinkedIn-sourced data to your CRM.

• The platform can automatically create and update contact records with information gathered from LinkedIn profiles, enriching your CRM data without manual entry.

• Outly's integrations are specifically optimized for B2B sales workflows.

Email Platform Compatibility

• Designed specifically for Gmail and Google Workspace (formerly G Suite) users.

• If you use these platforms, the integration is seamless, but the tool does not work with other email providers like Outlook or Yahoo.

• This Gmail-centric approach creates an excellent experience for Google users but is a non-starter for teams using other email platforms.

• Offers the broadest email compatibility, supporting Gmail, Google Workspace, Outlook, and custom SMTP configurations.

• This flexibility makes it suitable for teams with diverse email setups or organizations that use multiple email providers.

• The platform maintains a consistent user experience regardless of the underlying email service.

• Supports major email providers including Gmail, Google Workspace, and Outlook.

• The platform's focus is less on which email system you use and more on how your email prospection coordinates with LinkedIn activity.

• This approach works well for professionals who prospect on LinkedIn before moving conversations to email, regardless of which email platform they prefer.

LinkedIn Integration

• Has no native LinkedIn functionality .

• For users who need to coordinate email and LinkedIn prospection, this means managing separate tools and manually tracking cross-platform communications.

• While this limitation is expected given GMass's email focus , it creates extra work for sales professionals who use LinkedIn extensively.

• Offers limited LinkedIn integration through its multi-channel campaigns.

• You can include LinkedIn touchpoints as manual tasks within sequences and track their completion, but the platform doesn't automate LinkedIn actions.

• This approach helps coordinate LinkedIn activities with email campaigns but still requires manual LinkedIn work.

• Was built specifically for automatisation LinkedIn and excels in this area.

• The platform can automatically send connection requests , view profiles, follow accounts, and send messages all with personalization and safety measures to prevent account restrictions.

• Its dedicated residential IP system and mobile API access create the safest automatisation LinkedIn I've tested.

Most impressively, Outly's smart throttling system automatically adjusts LinkedIn activity levels based on account signals, pausing or slowing down if LinkedIn starts showing warning signs. This proactive approach to account safety has helped thousands of users automate LinkedIn prospection without facing restrictions.

Other Third-Party Connections

• Integrates seamlessly with other Google services like Calendar, Drive, and Sheets.

• For non-Google integrations, the platform relies primarily on Zapier connections , which include hundreds of possible app combinations but require separate configuration and subscription.

• This approach works well for Google-centric workflows but may feel limited for teams using diverse software ecosystems.

• Provides the most comprehensive third-party integration ecosystem , with native connections to tools like Slack, Calendly, Zoom, and various data enrichment services.

• Also supports Zapier, Integromat, and custom API connections for advanced integration needs.

• This extensive connectivity makes Mailshake particularly valuable for teams that use multiple specialized tools.

• Offers focused integrations with tools commonly used alongside LinkedIn prospection, i ncluding calendar booking systems, webinar platforms, and data enrichment services.

• Standout integration is with LinkedIn Sales Navigator, allowing you to leverage Navigator's advanced search and filtering while automating prospection through Outly a powerful combination for B2B prospecting.

Workflow Automation

• Provides strong email workflow automation , including scheduled sending, automatic follow-ups based on recipient behavior,

• And auto-responses for specific engagement types.

• These fonctionnalités work exceptionally well within the email context but don't extend to other parts of the sales process.

• Excels with end-to-end workflow automation across channels.

• Can automatically move leads between sequences based on engagement, assign leads to team members based on rules, and trigger actions in connected systems like your CRM.

• For équipes commerciales with defined proce sses, these automation capabilities can save hours of manual work each week.

• Focuses on automating the LinkedIn-to-email transition in prospecting workflows.

• Can automatically detect LinkedIn connections who haven't responded, move them to email prospection sequences, and track engagement across both platforms.

• This specialized automation is particularly valuable for B2B sales professionals who use LinkedIn as their primary prospecting channel.

For teams that need comprehensive integration with CRMs and other business tools, Mailshake provides the most robust ecosystem with deep connections to popular platforms and extensive customization options.

GMass vs Mailshake vs Outly: Analytics & Reporting

GMass offers straightforward email metrics, Mailshake provides comprehensive campaign analytics, while Outly excels at cross-platform engagement tracking.

GMass	Mailshake	Outly
⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐⭐⭐

Effective analytics and reporting capabilities help you understand what's working in your prospection and where improvements are needed. In this section, I'll compare how each platform handles:

• Email engagement tracking
• LinkedIn analytics
• Campaign performance reporting
• A/B testing capabilities
• Data visualization

Email Engagement Tracking

• Provides real-time tracking of opens, clicks, replies, and unsubscribes—all accessible directly from your Gmail inbox.

• Sends you daily engagement reports summarizing campaign activity, with links to view full details.

• GMass lacks some of the advanced engagement tracking found in dedicated platforms.

• Offers the most comprehensive email engagement tracking .

• Tracking time-based engagement patterns, link-specific clicks, and email client information.

• Automatically calculates key performance indicators like reply rates and engagement rates, making it easy to assess campaign effectiveness at a glance.

• Provides solid email tracking capabilities similar to GMass, with a focus on how email engagement relates to previous LinkedIn interactions.

• The platform's unique strength is connecting the dots between LinkedIn and email engagement, showing you which LinkedIn interactions led to the highest email response rates.

LinkedIn Analytics

• Doesn't offer any LinkedIn analytics , which is expected given its email-only focus.

• For users who run LinkedIn campaigns alongside GMass, this means managing and analyzing those efforts in separate systems.

• Offers basic LinkedIn activity tracking as part of its multi-channel campaigns.

• You can track completion of LinkedIn-related tasks and manually record outcomes

• But the platform doesn't provide automatic LinkedIn engagement metrics or detailed analytics specific to LinkedIn performance.

• Excels with comprehensive LinkedIn analytics , tracking connection request acceptance rates, message response rates, profile view engagement, and content interaction.

• The platform's "Account Health" dashboard provides unique insights into your LinkedIn activity levels relative to platform limitations, helping you maximize prospection while maintaining account safety.

Most impressively, Outly correlates LinkedIn engagement metrics with prospect characteristics, helping you identify the prospects most responsive to your prospection . This data-driven approach allows you to refine your targeting based on actual engagement patterns continuously.

Campaign Performance Reporting

• Provides straightforward campaign reports that focus on key email metrics.

• These reports are delivered directly to your inbox and can be accessed through a dedicated GMass dashboard.

• The platform's strength is simplicity ,you get clear metrics without needing to navigate complex reporting interfaces.

• Stands out with comprehensive campaign reporting that includes team performance metrics, channel comparison data, and detailed funnel analysis.

• The platform automatically identifies top-performing campaigns and messages, highlighting what's working best.

• For teams managing multiple campaigns , these insights help quickly identify and replicate successful approaches.

• Offers solid campaign reporting with a unique focus on cross-platform performance.

• The platform shows how prospects progress from LinkedIn connection to conversation to email engagement, providing visibility into the entire prospection funnel.

• This integrated view helps you understand where prospects drop off and which combination of touchpoints drives the best results.

A/B Testing Capabilities

• Includes basic A/B testing that allows you to test different subject lines within a single campaign.

• The platform automatically distributes variants to your recipient list and reports on which version performed better.

• While useful, this testing is limited to subject lines and doesn't extend to other message elements.

• Provides comprehensive A/B testing capabilities that extend beyond subject lines to include message content, sending times, and sequence structures.

• Can automatically identify winning variants based on opens, clicks, or replies, and apply them to remaining recipients in a campaign.

• For teams focused on continuous optimization, these testing fonctionnalités offer significant value.

• Offers solid A/B testing for both LinkedIn messages and email follow-ups .

• The platform's unique strength is testing different LinkedIn-to-email transition points, helping you identify when to move conversations from LinkedIn to email for optimal engagement.

• This specialized testing addresses a common challenge in cross-platform prospection strategies.

Data Visualization

• Presents analytics in straightforward tables with minimal visualization.

• This approach prioritizes clarity over complexity , making it easy to understand campaign performance quickly.

• For users who prefer more visual representations, GMass's reporting may feel somewhat limited.

• Excels with comprehensive data visualization including performance graphs, funnel visualizations, and comparative charts.

• The platform's dashboard provides both high-level overviews and detailed breakdowns, allowing you to identify trends and patterns that might not be apparent in raw data.

• These visualizations make Mailshake particularly valuable for data-driven teams.

• Offers good data visualization with a focus on LinkedIn safety metrics and cross-platform engagement.

• The platform's unique "Account Health" visualization shows your LinkedIn activity relative to safety thresholds, helping you maximize prospection without triggering restrictions.

• For professionals focused on LinkedIn prospecting, these specialized visualizations provide valuable insights not available in other tools.

GMass vs Mailshake vs Outly: Tarifs & Value

GMass offers the most affordable entry point, Mailshake provides the most fonctionnalités per dollar for équipes commerciales, while Outly delivers the best LinkedIn safety ROI.

For professionals focused on LinkedIn prospection who need specialized insights into platform-specific performance and account safety, Outly offers unique analytics that directly address these concerns.

Tarifs often becomes the deciding factor when choosing prospection tools, especially for petites entreprises and startups. In this section, I'll provide a detailed breakdown of each platform's tarifs structure and the value you can expect at each tier.

GMass Tarifs Breakdown

Standard: $25/mo paid monthly

• Unlimited email campaigns

• Campaign scheduling

• Automatic follow-ups

• Google Sheets integration

• Email personalization

• Open and click tracking

Premium: $39.95/mo paid monthly (price increasing from $35 in January 2026)

• Everything in Standard

• Reply management and detection

• A/B testing for subject lines

• Team collaboration fonctionnalités

• Reporting and analytics

• API access

Professional : $55/mo paid monthly

-The Professional plan finally comes with all the fonctionnalités where you can fully experience GMass and use it properly.

Mailshake Tarifs Breakdown

Starter : $29/mo paid monthly

• Automate email sequences to streamline communication and save time on repetitive tasks.

• Enjoy up to 250 monthly email sends, providing limited opportunity to reach your customers.

• Benefit from unlimited warmup, A/B testing, and AI email writing with SHAKEspeare, allowing you to refine and personalize your strategies for maximum impact.

Email Outreach: $49/mo paid monthly

• Engage with up to 5,000 recipients per campaign, extending your reach and amplifying the impact of your messaging.

-Integrate with Salesforce, Pipedrive, or Hubspot.

-Access over 1,000 integrations via Zapier.

-Engage with up to 5,000 recipients per campaign, among others.

Sales Engagement: $99/mo paid monthly

• Everything in Email Outreach

• Phone dialer integration

• Social selling fonctionnalités

• Team collaboration tools

• Advanced reporting and analytics

• Salesforce and HubSpot integration

• Priority support

The platform does offer a 14-day essai gratuit with full access to fonctionnalités, which is sufficient to evaluate the system but may not allow time for seeing long-term campaign results.

Outly Tarifs Breakdown

5Basic:$39/month billed monthly

• 1 active campaign
• Limited daily quotas
• Advanced dashboard & reports
• Complete performance automation

Advanced: $79/month billed monthly

• Unlimited active campaigns
• Full daily quotas
• Advanced dashboard & reports
• Complete performance automation
• A/B testing
• Personal inbox
• Webhook & Zapier integration
• Export leads into CSV

Professional : $99/month billed monthly

• Unlimited active campaigns
• Full daily quotas
• Advanced dashboard & reports
• Complete performance automation
• A/B testing
• Personal inbox
• Webhook & Zapier integration
• Export leads into CSV
• Team management
• Activity control

Who Should Choose Each Platform Based on Budget ?

GMass is the best choice if:

• You're on a tight budget but need professional email automation

• You're a Gmail user looking for the most affordable power-user tools

• You need unlimited campaigns and contacts without scaling costs

• You want to test email automation with a genuinely useful free plan

Mailshake is the best choice if:

• Your prospection volume and conversion value justify $59-99 per user

• You need comprehensive multi-channel capabilities in one platform

• Your sales process requires sophisticated team collaboration

• You're willing to invest more for advanced analytics and integrations

Outly is the best choice if:

• LinkedIn is a critical business development channel for your company

• You've experienced or are concerned about LinkedIn account restrictions

• The professional impact of LinkedIn limitations would exceed the cost

• You need specialized fonctionnalités not available in general-purpose tools

Outly's tarifs model differs significantly from both GMass and Mailshake as it charges flat-rate rather than per user.

During my testing, I found this approach can be more cost-effective for teams where multiple people collaborate on prospection using a single LinkedIn presence.

Mailshake emerges as the best overall choice because it delivers the most robust set of fonctionnalités per dollar, especially for équipes commerciales looking to scale with email prospection, CRM integrations, A/B testing, and multi-channel capabilities like phone and social selling.

GMass vs Mailshake vs Outly: Avantages & Limites

After spending three months testing these tools across multiple campaigns, here's my comprehensive breakdown of each platform's strengths and weaknesses:

GMass Avantages & Limites

Avantages	Limites
✅ Seamless Gmail integration provides the most natural email workflow	❌ Limited to Gmail and Google Workspace users only
✅ Extremely affordable starting at just $29.95/month	❌ No automatisation LinkedIn or integration
✅ Direct Google Sheets connection for real-time mail merge data	❌ Basic analytics compared to dedicated platforms
✅ Minimal learning curve, especially for Gmail users	❌ Limited team collaboration fonctionnalités
✅ Unlimited campaigns and recipients on all plans	❌ No multi-channel capabilities beyond email
✅ Free plan available for sending up to 50 emails per day	❌ No visual sequence builder for complex campaign flows
✅ Lightweight browser extension doesn't slow down Gmail	❌ Automated follow-ups only available on Premium plan

Mailshake Avantages & Limites

Avantages	Limites
✅ Comprehensive multi-channel capabilities (email, phone, social)	❌ Starting price at $29/month per user with limited sends
✅ Advanced sequencing with visual builder and branching logic	❌ Steeper learning curve due to feature complexity
✅ Robust team collaboration and performance tracking	❌ No free plan after trial period ends
✅ Extensive CRM and third-party integrations	❌ Key fonctionnalités like phone dialer restricted to higher-tier plans
✅ Sophisticated A/B testing across all message elements	❌ No native automatisation LinkedIn
✅ Detailed analytics and data visualization	❌ Campaigns require more setup time than GMass
✅ Works with multiple email providers, not just Gmail	❌ Can feel overwhelming for simple email campaigns

Outly Avantages & Limites

Wow your leads by cloning yourself and sending personalized videos and voice notes to each lead on LinkedIn.

If you don't reply to leads within 5 mins, your chances of converting them fall by 50%. Our AI replies on your behalf instantly! (and yes, you can train it)

Don't shoot in the dark. Get detailed analytics on what's working

Outly allows you to invite other team members, so that they can add their LinkedIn Account, run prospection campaigns and get amazing results just like you.