If your emails to Outlook or Hotmail suddenly bounce back with a 550 5.7.1 Message rejected: Message lacks SPF/DKIM/DMARC Auth Records error, you are not alone. Microsoft is slowly rolling out a new requirement for all incoming mail: a DMARC record which is making rounds at the mail ops list.
You might see this bounce message even if your email delivery has been working perfectly for years, and even if you already have valid SPF and DKIM records in place. Microsoft is simply tightening its security net, and domains without a DMARC policy are starting to get blocked.
The Quick Fix: Add a Basic DMARC Record
To get your mail flowing to Microsoft servers again, you need to add a TXT record for DMARC to your domain’s DNS settings. If you just want to pass the check without changing how your mail is handled, use a basic “none” policy.
Add a TXT record to your domain with the hostname _dmarc and the following value:
v=DMARC1; p=none;Setting it up in cPanel
If your InterServer hosting account uses cPanel, you do not have to add this record manually. Log into cPanel, navigate to the Email Deliverability tool, and click “Manage” next to your domain. The system will detect the missing DMARC record and give you a one-click option to install a standard record.
A Warning About DMARC Reporting Emails
There are more specific and restrictive DMARC policies you can set up, which involve adding an email address to your record to receive aggregate reports on who is sending mail on behalf of your domain.
Here is our advice: If you do not actively plan on reading and analyzing DMARC reports, do not add an email address to your record. Keep your record simple.
If you do decide to add an email for reports, never use a forwarded email address. DMARC report emails look extremely similar to spam filters. If you forward these reports to a Gmail address, the Sender Rewriting Scheme (SRS) forwarding will cause Gmail to heavily delay or throttle the emails—bizarrely, this happens even when Gmail’s own servers are the ones generating and sending the DMARC report.
