Mautic Multi Domain Plugin
Overview
The Friendly Multi Domain Plugin lets organizations manage multiple brands, websites, and sender domains within a single Mautic instance.
Friendly built it in 2021 to solve a common problem in complex organizations: companies often run several brands or business units but want marketing automation managed centrally. Doing that under one sender domain creates real deliverability risk — mailbox providers judge reputation per domain, so one brand's mistakes can hurt inbox placement for all of them.
The plugin fixes this by letting each brand send from its own domain, with its own isolated sender reputation, engagement history, and tracking/landing pages — while contacts, campaigns, and forms all stay centrally managed. No separate Mautic instance per brand required.
What started as Friendly's first Mautic plugin is now an established open-source project with 50 GitHub stars, 24 forks, and multiple external contributors — exactly what open source should do: solve a real problem, share it, and improve it together with the community.
Background and context
Friendly is a Swiss provider of privacy-friendly marketing automation and web analytics solutions based on open-source technologies, with Mautic as the technological foundation of our marketing automation offering.
Working with organizations that manage multiple brands, we kept hitting the same requirement: the operational efficiency of one centralized Mautic instance, without losing each brand's distinct domain identity. Separate instances mean extra infrastructure and maintenance; one shared domain across brands creates inconsistent customer experience and deliverability risk, since mailbox providers judge sender reputation per domain — one brand's mistakes can hurt inbox placement for all of them.
This led Friendly’s team to develop the Friendly Multi Domain Plugin in 2021 — Friendly's first Mautic plugin. The goal: one Mautic installation serving multiple brands and domains, each with its own sending identity and reputation, without losing the benefits of centralized automation.
Since then, it's grown from an internal solution into a public open-source project, used and improved well beyond Friendly itself.
Implementation
The Friendly Multi Domain Plugin extends Mautic with multi-domain capabilities while preserving centralized management within a single instance.
Among other capabilities, the plugin can dynamically use the appropriate tracking domain based on the sender email address. It replaces relevant domains in email elements such as tracking links, unsubscribe links, webview links and tracking pixels.
It also supports rewriting tracking JavaScript domains based on the domain from which the tracking script is requested. This helps organizations use brand-specific tracking domains rather than exposing the central Mautic domain.
For marketers, the result is that multiple brands can operate from one Mautic environment while maintaining their respective domain identities across important customer-facing touchpoints.
The plugin has also evolved technically over time. It includes REST API capabilities for retrieving, listing, creating, editing and deleting multi-domain configurations and integrates with Mautic's permission system.
Email and deliverability
For emails, the plugin can dynamically use the appropriate tracking domain based on the sender email address. It replaces the central Mautic domain in elements such as tracking links, unsubscribe links, webview links, and tracking pixels.
This is important not only for branding, but also for email deliverability. Modern email authentication and reputation increasingly depend on alignment and consistency between the domains recipients and mailbox providers encounter. Sending an email as one brand while routing clicks and tracking through an unrelated central domain creates a less coherent sending identity and can weaken the separation between brands.
With the Multi Domain Plugin, each brand can use its own sending and tracking domain. This makes it possible to build a more consistent domain identity and helps prevent the email activity of one brand from unnecessarily affecting the reputation and deliverability strategy of another.
Authentication mechanisms such as SPF, DKIM, and DMARC, together with brand-specific sending practices and infrastructure, can then be configured around each brand's domain rather than forcing unrelated brands to operate under a single identity.
Website tracking
The same principle extends beyond email.
Mautic normally exposes the domain of the central Mautic installation through its tracking JavaScript and related requests. In a multi-brand environment, this could mean that visitors to several otherwise independent websites all communicate with the same recognizable Mautic hostname.
The plugin allows the tracking JavaScript domain to be rewritten according to the domain from which the tracking script is requested. Each website can therefore use its own branded tracking domain while the requests are still handled by the same underlying Mautic installation.
For example, Brand A and Brand B can each load Mautic tracking through their respective domains rather than exposing a shared central mautic.company.com domain.
This keeps the technical marketing infrastructure in the background and provides a more consistent first-party experience across each brand's website.
Forms
Multi-domain handling also extends to Mautic forms.
Forms embedded across different brand websites can operate through the appropriate brand-specific domain rather than exposing the central Mautic hostname. Form-related requests and URLs can therefore remain consistent with the website on which the form appears while submissions are still processed centrally by the same Mautic instance.
This is particularly useful when Mautic is used across several independent websites. Visitors can interact with a Brand A form through Brand A's domain and a Brand B form through Brand B's domain, even though both forms, contacts, campaigns, and subsequent automations are managed within the same Mautic installation.
Together with domain-specific tracking, this means the brand identity can remain consistent across the complete journey:
Email → tracking link → website → page tracking → form → Mautic automation
The customer interacts with the domain of the relevant brand throughout that journey, while the organization retains a single centralized Mautic environment behind the scenes.
Centralized Mautic, decentralized domain identities
For marketers and administrators, the result is a useful combination: centralized marketing automation with decentralized domain identities.
Multiple brands can share the same Mautic environment, contact database, campaign engine, forms, segments, and administrative infrastructure while maintaining their respective domains across:
Sender addresses and email identities
Email tracking and redirect links
Tracking pixels
Unsubscribe and webview links
Website tracking JavaScript
Tracking requests
Embedded forms and form-related requests
Customer-facing Mautic URLs
This separation improves branding and provides a cleaner foundation for managing deliverability across multiple brands without requiring a separate Mautic installation for each one.
The plugin has also evolved technically since its original release in 2021. It provides REST API capabilities for retrieving, listing, creating, editing, and deleting multi-domain configurations and integrates with Mautic's permission system, making it suitable not only for individual installations but also for larger, centrally managed Mautic environments.
Impact and results
The strongest evidence of the project's impact is that it has grown well beyond the original use case that led Friendly to develop it in 2021.
What began as an internal solution for managing multiple brands within a single Mautic installation has developed into a long-running open-source project used in real production environments, supported by external contributors, and discussed within the wider Mautic community.
Proven across multiple Mautic generations
The Friendly Multi Domain Plugin has been supported since Mautic 3 and has continuously evolved alongside Mautic, with the current version supporting Mautic 7.
Maintaining compatibility across several major Mautic generations demonstrates that the plugin is not a one-off customization, but an actively maintained solution that has adapted as Mautic's architecture and ecosystem have evolved.
Active production use
Today, 20 Friendly customers actively use the Multi Domain Plugin in their Mautic environments.
These organizations use the plugin to centrally manage marketing automation across multiple brands, websites, or domains without having to operate a separate Mautic installation for each one.
This provides a tangible operational benefit: organizations can consolidate infrastructure, maintenance, contacts, campaigns, forms, and automation while preserving brand-specific sending, tracking, form, and website domains.
For organizations with complex brand structures, this means less infrastructure and administrative overhead without sacrificing domain identity or the separation needed for a sound email deliverability strategy.
Open-source adoption and contribution
The plugin is publicly available as open-source software and has attracted significant interest from the Mautic ecosystem. As of September 2026, the GitHub repository has:
50 GitHub stars
24 forks
7 listed contributors
Contributions from developers outside Friendly
Continued development and maintenance more than five years after its original release
External contributions are particularly important to the project's success. They demonstrate that multi-domain operation is not simply a Friendly-specific requirement, but a problem encountered by other organizations and developers working with Mautic.
The project therefore reflects one of the core strengths of open source: a solution developed for a real operational challenge can be shared, adopted, improved, and maintained together with the wider community.
Interest from the Mautic community
Interest in multi-domain Mautic setups extends beyond installations of the plugin itself. The topic has also generated significant engagement through conference presentations and educational content.
A dedicated Mauticon presentation about multi-domain Mautic has received more than 2,300 views, showing broader community interest in the architecture and the problems it solves.
Joey Keller's practical Multi Domain Plugin how-to tutorial has received more than 4,500 views, providing Mautic users with step-by-step guidance for implementing the approach in their own environments.
Together, the production installations, external contributions, GitHub activity, conference interest, and thousands of tutorial views show that multi-domain marketing automation addresses a genuine and recurring requirement within the Mautic ecosystem.
More than five years after its first release, the Friendly Multi Domain Plugin continues to solve the same fundamental challenge it was created for: giving organizations the efficiency of one centralized Mautic platform while allowing individual brands to maintain their own domain identity, tracking infrastructure, and deliverability strategy.
Lessons learned
The Multi Domain Plugin began as a solution to a practical challenge we faced ourselves. Publishing it openly allowed other developers and Mautic users not only to benefit from the solution, but also to improve it.
The project has also demonstrated the importance of long-term maintenance. Rather than publishing the plugin once and abandoning it, Friendly continues to maintain and update it as Mautic evolves.
Future plans
Our primary commitment is straightforward: keep the Friendly Multi Domain Plugin actively maintained, production-ready, and compatible with future Mautic releases.
The plugin has been part of the Mautic ecosystem since 2021 and has already evolved across multiple major Mautic generations, from Mautic 3 through Mautic 7. We intend to continue that journey as Mautic itself evolves.
Future development will focus on maintaining compatibility with Mautic's changing architecture, improving reliability and usability, and extending the plugin where new multi-domain requirements emerge.
Our long-term goal remains the same as when we started in 2021: make it practical for organizations to operate multiple brands and domains from one Mautic installation—without compromising brand identity, tracking consistency, or the foundations of good email deliverability.
Community contribution
Community contribution is one of the defining characteristics of this project.
Friendly originally developed the Multi Domain Plugin and made the source code publicly available. Since then, the project has grown into a collaborative open-source effort, with developers and organizations from across the Mautic ecosystem contributing their experience and improvements.
This collaboration is especially valuable because true multi-domain capability can touch almost every part of a marketing automation platform. Email sending and tracking are only the beginning. Domains can affect tracking scripts and pixels, forms, redirects, unsubscribe and webview URLs, landing pages, APIs, permissions, and many other areas of Mautic.
Supporting multiple domains consistently across all of these components is therefore an ongoing technical challenge—particularly as Mautic itself continues to evolve.
Today, seven contributors are listed on GitHub, while the repository has accumulated 50 stars and 24 forks. External developers have contributed meaningful enhancements, including API functionality, integration with Mautic's permission system, and improvements that have helped extend the plugin beyond Friendly's original requirements.
We are especially grateful to Kuzmany, Leuchtfeuer, and Surge Media for their contributions and involvement in the project, as well as to everyone who has reported issues, proposed improvements, tested releases, or contributed code.
Within Friendly, special recognition goes to Matic Mzagmajster, who has become the driving technical force behind the plugin and continues to lead its development and compatibility with new Mautic releases.
This evolution is particularly important to us. The Multi Domain Plugin is no longer simply a Friendly-internal development whose source code happens to be publicly accessible. It has become software that other members of the Mautic ecosystem use, fork, test, improve, and contribute back to.
That is exactly the kind of open-source collaboration we want to support as a company building on Mautic: solve a real problem, share the solution, and make it better together with the community.
Supporting materials
GitHub repository:
https://github.com/FriendlyDotCH/mautic-multi-domain
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