Microsoft (Outlook.com and Microsoft 365) · permanent error
550 5.6.241: HVE: From header missing or invalid
The message submitted through HVE has no valid From header, or the header is formatted incorrectly.
- Microsoft
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 550 5.6.241
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
550 5.6.241 Mandatory From Header is missing or invalid.
What it means
HVE requires every message to carry a valid From header. If it is missing, or its value is not a correctly formatted address, the submission is rejected with 550 5.6.241. The cause is in how the application builds the message. It mirrors Microsoft 365's general requirement for a valid From address, which elsewhere produces 5.7.512.
Common causes
- The application omits the From header.
- The From header has a malformed address, for example without angle brackets.
How to fix it
- 01Set a From header with a valid address on every message.
- 02Use the format Name <address@domain>.
- 03Check the raw message after any template processing.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
- Email nondelivery reports and SMTP errors in Exchange Onlinelearn.microsoft.com
Related codes
- 5.7.512Message has no valid From address.Microsoft 365 rejected the message because its From header does not contain a valid email address, as RFC 5322 section 3.6.2 requires.
- 550 5.6.240HVE: MIME header not allowed.The message submitted through HVE contains a MIME header that the service does not permit.
Further reading
All 111 Microsoft codesEvery code in the wikiPaste your own bounce