DMARC-SRG is a PHP-based open-source tool designed primarily for parsing DMARC aggregate reports. It allows users to process XML reports, store the data in a database, and then generate summary reports and a viewer for the data. This means it handles the core task of interpreting DMARC data, which is crucial for any DMARC implementation.

As a self-hosted solution, DMARC-SRG gives us complete control over our data and infrastructure. We found its primary strength in its ability to quickly ingest and present DMARC data, offering insights into email authentication results (SPF, DKIM, DMARC). However, being a basic parser, it focuses strictly on DMARC reporting and does not extend to other email deliverability aspects like SPF flattening, blocklist monitoring, or a dedicated API for integrations.

Our experience with DMARC-SRG's user interface is that it's functional but quite basic. The viewer provides a straightforward tabular and graphical representation of DMARC data, allowing us to quickly see authentication results, sending sources, and DMARC policy compliance. For users accustomed to modern SaaS platforms, the interface might feel a bit spartan. It provides the necessary data, but without the polish and advanced filtering often seen in commercial tools.

Setting up DMARC-SRG requires a degree of technical expertise. We needed to have a web server with PHP and a database configured, as well as set up a cron job to automate the parsing of incoming DMARC XML reports. This isn't a 'set it and forget it' kind of tool, as it demands ongoing maintenance and updates from the user. For those who enjoy getting their hands dirty with server administration, it's a perfectly capable solution.

As an open-source project, DMARC-SRG operates without a formal commercial support team. This means we rely heavily on the community and available documentation for assistance. Issues or questions are typically handled through its GitHub repository, where users can submit bug reports or seek advice. This model works well for technically adept individuals or teams who are comfortable troubleshooting and finding solutions independently.

While community support can be robust, it lacks the guarantees, dedicated channels, and service level agreements (SLAs) that come with paid commercial products. If we encountered a critical issue, we wouldn't have a direct line to an expert for immediate resolution, which can be a significant consideration for businesses with strict operational requirements. It's a 'you're on your own, but the community might help' kind of situation, which has its charm for the right user.

DMARC-SRG is best suited for organizations or individuals who have specific needs and technical capabilities. We found it ideal for those who prefer to host solutions on their own infrastructure, have PHP and server administration skills, and want full control over their DMARC data without recurring subscription fees.

However, its suitability varies significantly across different user types:

- **MSPs (Managed Service Providers)**: Less suitable. It lacks multi-tenancy features, API access for integration, and commercial support necessary for managing DMARC for multiple clients efficiently. An MSP would likely need to build extensive custom tooling around it.

- **Enterprise**: Less suitable. Enterprises typically require advanced features, robust commercial support, high availability, and scalability that a self-hosted open-source project may not inherently provide. The lack of an API for integration with existing systems is also a major drawback.

- **SMB (Small to Medium Business)**: Less suitable, unless they have dedicated IT staff with the necessary technical skills. SMBs often prefer user-friendly SaaS solutions that require minimal setup and maintenance, allowing them to focus on their core business rather than server management. It's great if you have a developer on staff who loves open source, though!