Is it okay to use the plus sign in the RUA email address of a DMARC record?
Michael Ko
Co-founder & CEO, Suped
Published 17 Jul 2025
Updated 19 Aug 2025
8 min read
When setting up DMARC, ensuring that your reports are delivered correctly is crucial for monitoring your email ecosystem and identifying potential spoofing attempts. The + sign, often used for email aliasing (or 'sub-addressing'), offers a convenient way to filter incoming messages. The question often arises: is it acceptable to use this feature within the rua email address of a DMARC record? This is a common practice that can streamline report management.
Many email administrators and marketers adopt plus addressing to automatically sort emails into specific folders or to track the source of an email address. For instance, using yourname+newsletter@example.com allows you to identify that an email came from a newsletter subscription, even though it's all routed to yourname@example.com. This method simplifies organization and can be particularly useful for managing various types of automated reports, including DMARC aggregate reports.
The short answer is yes, using the plus sign in the rua email address of a DMARC record is generally perfectly acceptable and widely supported. Email standards, specifically RFC 5322, define the allowed characters in the local part of an email address, which includes the plus sign. This means that email systems are designed to handle these addresses correctly. Most sophisticated mail servers that send DMARC reports will process addresses with plus signs without issue.
The primary benefit of using plus addressing for your DMARC rua address is the ability to easily filter and manage incoming DMARC aggregate reports. Instead of having all reports land in a generic inbox, you can direct them to a specific folder or trigger automated actions based on the plus tag. For example, dmarc+rua@yourdomain.com clearly indicates that the incoming mail is a DMARC aggregate report, making it easier to separate from other emails.
While many DMARC record generators might not explicitly support or validate plus signs in their input fields, this is often a limitation of the tool itself, not an indication that the character is invalid. Registrars typically allow the creation of TXT records containing such email addresses without rejection. The crucial point is that the underlying email standard supports it, and major mail exchangers are configured to handle it. You can review the DMARC RFC 7489 documentation for further technical details.
Using plus addressing for DMARC RUA reports
To correctly implement DMARC with a plus-addressed rua address, your DMARC DNS record will look something like this:
This setup tells recipient mail servers to send aggregate reports (rua) to the specified email address. The p=none policy in this example is a good starting point for DMARC implementation, allowing you to monitor your email traffic without affecting delivery. If you're new to DMARC, it's recommended to properly set up DMARC records and reporting to ensure full protection and visibility.
One critical aspect to remember is that the email address specified in the rua tag must typically belong to the same domain where the DMARC record is published. If you need to send reports to a third-party domain (e.g., a DMARC monitoring service), that domain must publish specific authorization records to indicate consent. Without these records, recipient mail servers might not send reports to the external address, potentially causing missing RUA records to block email or prevent report delivery.
While rua reports are designed for automated processing, the plus sign helps in manual sorting if you're not using a dedicated DMARC reporting platform. However, for serious DMARC monitoring, it's often more efficient to use a specialized service that can parse and visualize these XML reports, providing actionable insights into your email authentication status. This is especially important given Microsoft 365's approach to DMARC reporting, where aggregate reports are sent to domains with valid rua addresses.
Considerations for DMARC reporting
While the plus sign is valid, there are still a few considerations to keep in mind to ensure smooth DMARC report delivery and processing. These include understanding the volume of reports you might receive, especially for domains with high email traffic, and how your mail server handles such volume.
Sometimes, high volumes of DMARC reports, especially from large senders like Google or Microsoft, can overwhelm a standard mailbox. Setting up a dedicated mailbox or using a specialized DMARC reporting service is usually preferable to avoid inbox clutter and ensure reports aren't missed. These reports, often in XML format, are not meant for human consumption and are best processed by automated tools.
Direct mailbox for reports
DMARC reports (RUA and RUF) are XML files. When sent to a direct mailbox, they are not human-readable and can quickly overwhelm an inbox, making manual analysis impossible. You would need to manually download and use an external parser, which is inefficient. This approach is prone to missing critical data due to volume or misfiling.
Volume: Can quickly flood a regular email inbox, making it unusable.
Readability: Reports are XML, not designed for human reading without parsing.
Analysis: Requires manual parsing or external tools, which is time-consuming.
Understanding the information in DMARC RUA and RUF reports is key to leveraging DMARC for email security. These reports provide valuable insights into email authentication, including SPF and DKIM alignment, and help you identify legitimate vs. fraudulent email streams originating from your domain. While plus addressing helps with initial routing, a robust DMARC monitoring solution is necessary for effective analysis and policy enforcement.
Optimizing DMARC report handling
To truly get the most out of DMARC reporting, especially with the high volume of data involved, it's best to automate the processing of these reports. While using a plus sign in your DMARC rua address is valid, it's only the first step in managing these valuable insights. Consider setting up a dedicated system or using a DMARC service.
Using a DMARC analysis service can significantly reduce the effort required to interpret these reports. These services parse the XML data, provide user-friendly dashboards, and offer alerts on suspicious activity. This enables you to quickly identify issues like email spoofing or misconfigurations of your SPF or DKIM records, which are essential for maintaining good email deliverability and avoiding email blacklists (or blocklists).
While rua reports are more frequently used, the ruf (forensic) reports are also important, though less commonly sent due to privacy concerns. Both rua and ruf tags can utilize plus addressing for better organization. The key is to manage these reports efficiently to ensure your DMARC policy is effectively protecting your domain. For further details on the specifications, consult the official DMARC overview on dmarc.org.
Views from the trenches
Best practices
Always verify that your DMARC record, including the RUA address, is correctly published in your DNS for proper report delivery.
If using an external DMARC reporting service, ensure the necessary authorization records are set up on your domain to permit report delivery.
Start with a `p=none` DMARC policy to monitor email traffic and understand authentication failures before enforcing stricter policies.
Use plus addressing to create dedicated mailboxes or filters for DMARC reports, simplifying organization and analysis.
Regularly review your DMARC aggregate reports to identify trends, misconfigurations, or potential spoofing attempts.
Common pitfalls
Assuming DMARC reports are human-readable, leading to overloaded inboxes and unanalyzed data.
Not configuring explicit authorization for third-party DMARC reporting services, resulting in reports not being delivered.
Failing to monitor DMARC reports, which means you miss crucial insights into your email authentication status and domain health.
Implementing a strict DMARC policy (e.g., `p=reject`) too early without sufficient monitoring and understanding of your email flows, causing legitimate emails to be rejected.
Overlooking subdomain DMARC policies; if not explicitly defined, they can inherit the parent domain's policy, which may not be appropriate.
Expert tips
Use DMARC reports in conjunction with SPF and DKIM authentication to gain a comprehensive understanding of your email sending infrastructure.
Leverage the `fo` tag in your DMARC record to specify failure reporting options, providing more granular control over forensic reports.
Integrate DMARC report processing with your existing security information and event management (SIEM) systems for centralized threat detection.
For very high-volume domains, consider setting up a dedicated sub-domain for DMARC reporting to isolate its DNS records and manage traffic more effectively.
Pay close attention to report volume fluctuations; sudden spikes or drops can indicate changes in legitimate traffic or new spoofing attempts.
Expert view
Expert from Email Geeks says the plus sign is a perfectly valid character for an email address, and most sophisticated sites sending DMARC reports will handle it without issue. A dedicated mailbox for aggregate reports is also best practice, as they are meant to be machine-parsed.
2024-01-18 - Email Geeks
Expert view
Expert from Email Geeks says the email address in the DMARC record must either be in the same domain as the DMARC record or a third-party domain that has published authorization records for it to work correctly.
2024-01-18 - Email Geeks
Final thoughts on DMARC RUA setup
Using a plus sign in the rua email address of a DMARC record is a valid and effective strategy for organizing your DMARC aggregate reports. It aligns with email standards and is supported by major mail providers. While it offers a basic level of report categorization, pairing this approach with a dedicated DMARC monitoring solution will provide the most comprehensive insights and efficient management of your email security posture.
Ultimately, the goal is to leverage DMARC reports to understand your email ecosystem better, protect your domain from impersonation, and enhance your overall email deliverability. The plus sign is a helpful tool in this process, but a robust strategy involves consistent monitoring and a clear understanding of what your DMARC reports are telling you.
Google or 
Microsoft, can overwhelm a standard mailbox. Setting up a dedicated mailbox or using a specialized DMARC reporting service is usually preferable to avoid inbox clutter and ensure reports aren't missed. These reports, often in XML format, are not meant for human consumption and are best processed by automated tools.
