Undelivered email to .mil accounts

Question

My company's email operates fully in Microsoft 365. Lately, users report that email messages that they send to recipients with mail.mil email addresses are not being delivered. I ran a message trace to find those email messages in our tenant, and the trace says that the emails are being delivered. I am at a loss as to what is happening to the messages. I have seen others reporting this issue on other forums, but I have not seen anyone who has produced a solution. Is there a solution out there that I just have not dug deep enough to find? Any help is appreciated.

Answer 1

If message trace shows delivered to the recipient domains, then your work is done. If the recipient domain accepts the messages, then its on them now to figure out what happened to them. Typically, when messages fail to a .mil org, its because it failed DMARC or DKIM. I would ask them to check their own logs since it shows delivered from your end. Could be they are being quarantined.

Answer 2

Did you ever figure this out? We're having the same issue..

Answer 3

Hello @David Gilliam ,

This seems to be a common issue that others are having as well, are your users getting non-delivery reports?

As Andy said, it is recommended that you check your DMARC, DKIM and SPF records, these are crucial for email delivery. If they are not up to date or configured incorrectly, your emails may be quarantined on the receiving end. Alternatively, you could try contacting the recipient's IT department. Sometimes, the problem may be on the recipient's end. Their email servers may block or filter your emails.

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". Note: Please follow the steps in [our documentation] to enable e-mail notifications if you want to receive the related email notification for this thread.