Over the weekend, Yahoo! experienced issues with DMARC reporting to email senders.  DMARC processing reports appeared garbled which rendered the reports unusable.  

What is a DMARC Report?

DMARC reports are critical to understanding email delivery.  They contain XML descriptions of email delivery results sent by Inbox Providers to email senders and DMARC reporting tools.  A DMARC report details email volume, SPF, DKIM and DMARC compliance information for a domain sending to that Inbox Provider. It is important for emailers to act upon the information in a DMARC report to improve their email delivery and protect their brand.

How does this affect Email Senders?

MxToolbox Delivery Center customers and others that sent email to Yahoo! over the weekend will not have accurate information on their DMARC reports back from Yahoo! This will appear as lower than normal email volume, but this should not affect compliance rates.

It is possible that Yahoo! will resend the information now that the issue has been corrected, but it is unlikely.  It is also possible that the data is no longer available or was corrupted at the source, so users can expect a hole in the data for the weekend.

Does this make DMARC less reliable?  How does this affect DMARC reporting?

This appears to be a one-time issue with Yahoo!   The issue appears to be DMARC reporting, and not DMARC compliance processing, so this does not affect email security or the value of DMARC as an email delivery technology nor does it seem to affect inbound email.  DMARC compliant email will always be prioritized over non-compliant email by large Inbox Providers like Google, Outlook.com and Yahoo!  The main issue is a short-term lack of information from one Inbox Provider, not an issue with DMARC itself.

MxToolbox Helps You Process DMARC Reports

If you have a single, small DMARC report to checkout, MxToolbox provides a free DMARC Report Analyzer.  This will give you good insight into how compliant your email was to a single Inbox Provider over a short period of time.

Getting DMARC compliant will improve your email delivery.  To achieve DMARC compliance, you need a DMARC Reporting tool like MxToolbox Delivery Center.  Delivery Center processes, aggregates and analyzes all your DMARC reports across all Inbox Providers.  You get a single interface to understand your SPF, DKIM and DMARC compliance across all your senders.