Operators building self-hosted email infrastructure face an early architectural decision: which platform to use for the application layer. The MTA layer choices (PowerMTA, Postfix, Postal) we covered in another post. The application layer choices are different: MailWizz, Acelle, and Sendy are the three commercial options most operators consider.
We work with customers on all three platforms across our managed services. The choice affects operational characteristics significantly. This post is our operator-level comparison of the three platforms based on production experience with each.
What each platform is
The three platforms serve overlapping but distinct operator profiles.
MailWizz
Founded 2013, originally as a self-hosted alternative to mainstream ESPs. Continues active development. Used by thousands of operators globally.
Architecture: PHP-based application with MySQL/MariaDB database. Designed for moderate to high volumes. Customer-facing features substantial.
Customer profile: small to large operators wanting a full-featured email marketing platform under their own control. Common among ESP resellers and operators serving multiple end-clients.
Licensing: commercial license required. €399 for self-hosted use, additional fees for multi-tenant operations.
Acelle Mail
Founded 2015, marketed as an alternative to MailWizz with different architecture and feature philosophy. Active development continues.
Architecture: PHP/Laravel-based application. MySQL/MariaDB. Cleaner codebase than MailWizz in subjective assessments. Modern Laravel patterns.
Customer profile: similar to MailWizz but with operators preferring modern PHP frameworks and cleaner code. Common in technical operator segments.
Licensing: commercial license. €399 typical pricing, similar to MailWizz.
Sendy
Founded 2011, specifically designed for Amazon SES integration. Smaller scope than MailWizz/Acelle but mature for its specific use case.
Architecture: PHP-based application optimized for SES. Smaller codebase than the other two.
Customer profile: operators committed to Amazon SES for sending. Wanting simpler self-hosted platform without ESP capabilities they don’t need.
Licensing: commercial license. $69 one-time purchase. Much cheaper than the alternatives.
Pricing comparison
The pricing differs significantly.
MailWizz
€399 for personal license (one operator using on their own domains) €999 for extended license (use on customers’ domains as well) Additional pricing for multi-tenant operations Subscription updates available for staying current
Acelle
€399 for similar use case (single operator) €799 for extended use Similar pricing structure to MailWizz
Sendy
$69 one-time purchase $199 for additional features Much lower up-front cost than alternatives
The Sendy pricing reflects its narrower scope. The MailWizz/Acelle pricing reflects broader functionality.
Functional comparison
The three platforms have different feature breadth.
MailWizz feature set
Subscriber management with custom fields and segmentation Campaign management with template editor Automation workflows List hygiene tools Bounce processing Feedback loop integration Multi-language support API for integrations Customer-facing interface for multi-tenant operations Multiple delivery server backends (PowerMTA, Postal, Amazon SES, generic SMTP) Detailed analytics
The feature breadth is the most comprehensive of the three.
Acelle feature set
Subscriber management with custom fields Campaign management with template editor Automation workflows List hygiene tools Bounce processing Feedback loop integration Multi-language support API for integrations Multi-tenant capability Multiple delivery server backends Modern admin interface
Similar to MailWizz in scope. Differences are in implementation details and UI philosophy rather than feature gaps.
Sendy feature set
Subscriber management (simpler than MailWizz/Acelle) Campaign management Basic automation List management Amazon SES delivery (primary) Limited other delivery backends Simpler admin interface Lower operational overhead
The narrower scope makes Sendy simpler operationally but less flexible than the others.
Technical comparison
The three differ in technical characteristics.
MailWizz technical
PHP application using legacy Yii framework patterns MySQL database Database schema is comprehensive but somewhat dated Performance scales reasonably to high volume Some technical debt visible in codebase Updates come regularly but not always smoothly
For operators with PHP expertise, the codebase is workable. For operators wanting modern frameworks, the legacy patterns may be friction.
Acelle technical
PHP application using modern Laravel framework MySQL database Cleaner schema design Modern PHP patterns throughout Performance scales reasonably Less technical debt than MailWizz
The Laravel-based architecture is more aligned with modern PHP practices. Operators with Laravel familiarity feel more comfortable.
Sendy technical
PHP application with simpler architecture MySQL database Smaller codebase Focused on Amazon SES integration Limited extensibility relative to the others
The simplicity is intentional. Operators wanting flexibility may find Sendy limiting; operators wanting focused functionality find it appropriate.
Operational characteristics
After working with customers on all three:
MailWizz operational reality
Installation: bounded but not trivial. Several hours for proper setup.
Ongoing operations: moderate complexity. Multiple components require attention.
Updates: regular cadence. Update process is bounded but requires care.
Customer support quality from MailWizz team: variable. Some questions receive detailed responses; others require community resources.
Community: active. Forums, third-party tutorials, integration documentation available.
Performance: scales to substantial volumes. Limitations emerge above 1M+ daily messages per instance.
Acelle operational reality
Installation: similar complexity to MailWizz.
Ongoing operations: moderate complexity. Modern framework makes some operations cleaner.
Updates: regular cadence with cleaner update procedures than MailWizz.
Customer support quality from Acelle team: generally responsive. Smaller team but engaged.
Community: smaller than MailWizz community but growing.
Performance: comparable to MailWizz. Similar scaling characteristics.
Sendy operational reality
Installation: simpler than MailWizz/Acelle.
Ongoing operations: lower complexity. Less to maintain.
Updates: less frequent updates. Stable codebase.
Customer support quality: bounded. Self-service emphasis.
Community: smaller than MailWizz; focused on SES-specific topics.
Performance: scales reasonably for moderate volumes. Less proven at very high volumes.
Use case fit
The platforms fit different operator profiles.
When MailWizz makes sense
Operators wanting full-featured platform with broad capability Operators serving multiple end-customers (multi-tenant) Operators with PHP expertise comfortable with the existing codebase Operators wanting the largest community of similar deployments
When Acelle makes sense
Operators wanting modern PHP framework architecture Operators with Laravel familiarity preferring that codebase Operators with technical preferences favoring clean code Operators wanting MailWizz-like capability with different implementation philosophy
When Sendy makes sense
Operators committed to Amazon SES for sending Operators wanting simpler self-hosted platform Operators with bounded marketing email needs Operators with cost constraints favoring lower upfront pricing
When none of these make sense
Operators wanting transactional-only infrastructure (PowerMTA or Postal alone may be more appropriate) Operators with very specialized requirements Operators at very high volume requiring custom development Operators preferring SaaS ESP convenience
Migration paths between platforms
Customers sometimes migrate between these platforms. The patterns:
From MailWizz to Acelle
Most common migration direction. Customers wanting modern framework architecture.
The migration involves data export from MailWizz and import into Acelle. The work is bounded but real. Templates, lists, and campaigns transfer with some adaptation.
From Acelle to MailWizz
Less common direction. Sometimes for specific features Acelle doesn’t have.
Similar migration work in reverse direction.
From Sendy to MailWizz/Acelle
Common when customers outgrow Sendy’s feature set. Migration involves more work because Sendy’s data model is simpler.
From MailWizz/Acelle to Sendy
Rare. Customers who realize they don’t need the full capability.
Migration costs
The migration work is typically 20-60 hours depending on:
- Number of subscribers
- Number of templates
- Number of campaigns and automations
- Customizations in the original platform
Plan for the migration work explicitly when considering platform changes.
Specific operational pitfalls
Each platform has specific operational issues operators should know about.
MailWizz pitfalls
Database performance issues at scale require tuning. Default MySQL configuration is inadequate for production volumes.
Background processing requires careful queue management. Cron jobs and worker processes need monitoring.
Email rendering across clients sometimes produces issues requiring template adjustment.
Some integrations require specific configurations not obvious from documentation.
Acelle pitfalls
Newer than MailWizz; some edge cases less documented.
Laravel framework upgrades occasionally require code adjustments.
Queue configuration requires Laravel queue understanding.
Some advanced features have fewer community resources for troubleshooting.
Sendy pitfalls
Amazon SES quotas affect operations. Increases require Amazon support requests.
Limited integration ecosystem compared to MailWizz/Acelle.
Customizations require PHP development beyond platform’s standard configuration.
Multi-tenant operations are less robust than the alternatives.
Customer profile observations
Patterns we observe about customers using each:
MailWizz customer base
Larger overall customer base. Wide range of operator profiles.
Common among ESP resellers serving multiple end-customers.
Common among operators in restricted-content categories where mainstream ESPs are not options.
Many operators in this segment came from MailWizz versions years ago and have built familiarity over time.
Acelle customer base
Growing customer base. More technical operators in the mix.
Common among operators preferring modern PHP architecture.
Some former MailWizz customers who migrated for the cleaner codebase.
Sendy customer base
Smaller, more focused customer base.
Common among bloggers, content creators, and smaller publishers.
Operators committed to Amazon SES for cost-effective sending.
Operators wanting simpler operational footprint.
What we have observed about platform stability
The three platforms have different stability characteristics.
MailWizz stability
Mature codebase. Years of production use across many operators.
Some legacy patterns can produce issues during updates. Update procedures benefit from careful testing.
Database stability is solid. Schema is well-established.
Performance under load is predictable.
Acelle stability
Stable for most operations. Newer than MailWizz so fewer accumulated production patterns.
Laravel framework provides some stability benefits (framework-level testing, standard patterns).
Some edge cases less stress-tested than MailWizz equivalents.
Sendy stability
Very stable codebase. Less surface area for issues.
Mature for its specific use case.
Limited adaptation to specific edge cases means some operational scenarios produce friction.
Integration ecosystem
The three differ in their integration ecosystems.
MailWizz integrations
Mature integrations with PowerMTA, Postal, Amazon SES, various SMTP services.
Third-party integrations for specific use cases.
Plugins and extensions available from community.
Comprehensive API for custom integrations.
Acelle integrations
Similar core integrations to MailWizz.
Smaller ecosystem of third-party integrations.
Modern API design facilitates custom integrations.
Sendy integrations
Primarily Amazon SES integration (this is its design focus).
Limited other integration options.
Some community workarounds for non-SES use cases.
Performance at scale
The three platforms scale differently.
MailWizz at scale
Scales reasonably to 1-2M daily messages per instance.
Beyond that, requires multiple instances or significant database tuning.
Some bottlenecks emerge at high volumes that require operational attention.
Most successful high-volume deployments use multiple MailWizz instances.
Acelle at scale
Similar scaling characteristics to MailWizz.
Modern framework may provide some scaling advantages.
Production data on very high volume deployments is limited (Acelle is newer).
Sendy at scale
Designed for moderate volumes.
Above 500K daily messages, alternative platforms may be more appropriate.
The simplicity that makes Sendy attractive at moderate volumes can limit it at higher volumes.
What we recommend for different operator profiles
Based on our customer experience:
For multi-tenant ESP operators
MailWizz is the typical recommendation. Mature multi-tenant capability, established community of operators in similar situations.
Acelle is a credible alternative for operators wanting modern architecture.
Sendy is not appropriate for multi-tenant operations.
For single-tenant operators with broad marketing needs
Either MailWizz or Acelle depending on technical preferences. Both serve this profile well.
For single-tenant operators with focused marketing needs
Sendy if Amazon SES integration is appropriate. Simpler operational footprint than the alternatives.
MailWizz or Acelle if more flexibility needed.
For transactional-focused operations
Consider whether you need an email marketing platform at all. PowerMTA or Postal directly may be more appropriate.
If a platform is needed for transactional, the choice depends on specific requirements.
For very high volume operations
Multiple instances of any platform, or custom development.
The single-instance scaling limits favor architectural patterns that distribute load across instances.
What we support across these platforms
For customers on our managed infrastructure:
We support MailWizz, Acelle, and Sendy deployments. The MTA layer (PowerMTA, Postal, our delivery infrastructure) connects to each platform.
For new customers, we typically recommend MailWizz unless specific factors favor alternatives. The recommendation reflects our greater experience operating MailWizz.
For customers with existing platforms, we work with whatever they have. The migration cost would exceed the operational benefit in most cases.
For customers choosing between platforms, we provide consultation based on their specific situation.
The longer-term considerations
Looking at the platforms’ trajectories:
MailWizz
Continues active development. Likely to remain the dominant self-hosted commercial platform for years.
The mature ecosystem produces stable operational outcomes for operators familiar with the platform.
Acelle
Continues development. Growing customer base.
The modern architecture positions it well for future framework evolution.
May continue gaining share from MailWizz for technical operators preferring modern patterns.
Sendy
Continues stable operation. The narrow scope limits growth potential but produces consistent value for customers in the segment.
Less competitive pressure on Sendy due to its specific positioning.
New entrants
The market does receive occasional new entrants. Listmonk (open-source), Postal (with MailWizz-like capability), various specialty platforms.
Most new entrants have not achieved meaningful customer adoption against the established players.
What does not work in this space
Some approaches we have seen that produce poor outcomes.
Frequent platform switching
Some operators switch platforms looking for the perfect fit. The migration costs typically exceed the marginal benefits.
Stable operation on appropriate platform beats frequent migrations.
Building custom
Some operators develop their own platform rather than using MailWizz/Acelle/Sendy. The development cost almost always exceeds the licensing cost.
Custom platforms make sense for very specific high-volume operations. For most operators, commercial platforms are cost-effective.
Avoiding all paid platforms
Some operators look for completely free alternatives. The free alternatives (Listmonk, basic Postal) have functional limitations.
The paid platforms’ license cost is small relative to operational value.
Multi-platform deployments without clear need
Some operators run multiple platforms simultaneously without clear architectural rationale. The complexity typically produces worse outcomes than single-platform operations.
The honest summary
Three platforms, three reasonable choices, three customer profiles served well.
MailWizz: broadest feature set, largest customer base, mature ecosystem. Acelle: modern architecture, cleaner code, growing customer base. Sendy: simpler scope, lower cost, focused on Amazon SES.
The right choice depends on operator profile. The wrong choice produces operational friction. The honest assessment of your specific situation produces good selection.
For our customer base, we support all three. The platform choice is one element of broader infrastructure decisions. The MTA layer, the operational practices, the customer relationships all matter beyond the platform itself.
For other operators reading this: the platform choice is bounded but real. Take the time to evaluate honestly. Consider operational characteristics beyond feature comparisons. The choice affects your operations for years.
The three platforms will continue serving the self-hosted email marketing segment. Customers will continue choosing among them based on specific characteristics. The pattern is sustainable for everyone involved.
The work of running email marketing well requires good platform plus good operational practices. The platform is one element. The operational practices are the larger factor in outcomes. Choose the platform appropriately, then invest in operational discipline. The combination produces sustainable email marketing operations.