Will Outlook accept your mail?
Since 5 November 2026, mail providers report that Outlook.com and Hotmail refuse part of the mail from domains that publish no DMARC record, even when SPF and DKIM pass. Microsoft has not confirmed the cause. Type a domain. We say whether it has a DMARC record that receivers can use, and give the record to publish if not.
Whether Outlook.com takes your mail, and the DMARC record to fix it.
A few seconds
The DMARC policy, the SPF record to the end, and the DKIM keys.
A few seconds
Who holds the name, its DNS, its mail and its website.
About fifteen seconds
The names that copy yours, and which of them are registered.
Counted at once
Or see it done for a domain we watch
Deliverability
Digital Footprint
Lookalikes
The bounce
550 5.7.1 Message rejected: Message lacks SPF/DKIM/DMARC Auth Records (AS9031519)
Senders first reported it on 5 and 6 November 2026, with no notice from Microsoft. It hits consumer Outlook.com and Hotmail addresses, and only part of the mail: a message that bounced has gone through when sent again. Keep the whole bounce message. The code AS9031519 is what marks this bounce; 550 5.7.1 alone is a common refusal with many causes.
What is known of the cause
Microsoft has not said. MXroute, Fastmail and MailRoute each found the bounce on domains that had SPF and DKIM passing and no DMARC record. MXroute and MailRoute now tell their customers to publish one. Not every report fits: one business sender's bounces also held an SPF failure (5.7.23). A DMARC record answers what the reports have in common. It is not a promise that Outlook.com takes every message.
The record to publish
The check gives it. A domain with no record gets v=DMARC1; p=none;, which asks receivers to do nothing to failing mail and so cannot cost you mail. A broken record gets the same record with only the fault fixed. If you already have a record that works, keep it: do not lower it to none, and do not add a second one. What each DMARC policy does.
If it goes on
If the bounce goes on after your DMARC record is visible, check that SPF or DKIM passes for the domain in the From address of the mail that bounced, and the envelope sender as well. Then send the full bounce messages, their UTC times, the receiving host names and the sending IP addresses to Outlook.com Sender Support.
Not the same as 5.7.515
Since May 2025, Microsoft refuses mail from senders of more than 5,000 messages a day that do not pass SPF, DKIM and DMARC, with 550 5.7.515. That rule is published. The AS9031519 bounce is a different code, and it has hit small senders.