Why are incoming emails disappearing without a bounce message?
External emails can vanish before reaching the inbox, spam folder, or generating a non-delivery report when aggressive mail filters or specific routing rules intercept them silently. This completely blocks expected notifications and customer messages without alerting the sender or recipient that delivery failed.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Contacting support to investigate delivery status
- 2Checking MTA-STS records
- 3Reviewing third-party mail filters and recipient logs
- 4Checking transport rules, defender actions, and hidden inbox rules
- 5Submitting the message to Microsoft using the Defender XDR portal for analysis
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“It's just being sent from [email protected]”source ↗
“some of our customers having external domains, when sending mail to domains that have MX at Outlook, are not reaching recipients' inboxes nor Junk/Spam folder, and mails are not rejected either.”source ↗
“I've got an email for zoom webinars that immediately gets delivered to deleted items.”source ↗
Where this came up
People with this problem also raised
- 3How to fix sync problems on large Outlook mailboxes
- 2Why do self-hosted emails keep going to spam?
- 2Automated notification emails only show IDs instead of client names
- 4How to handle guests who haven't RSVP'd by the deadline
- 3How to stop an email spam bomb attacking a user inbox
- 5Why do small businesses miss incoming phone calls?