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.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Contacting support to investigate delivery statusDid this help you?
- 2Checking MTA-STS recordsDid this help you?
- 3Reviewing third-party mail filters and recipient logsDid this help you?
- 4Checking transport rules, defender actions, and hidden inbox rulesDid this help you?
- 5Submitting the message to Microsoft using the Defender XDR portal for analysisDid this help you?
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
- 10Why do self-hosted emails keep going to spam?
- 2Why are legitimate vendor emails going to quarantine?
- 3Automated notification emails only show IDs instead of client names
- 12How to handle guests who haven't RSVP'd by the deadline
- 2Securence alternatives for email filtering