Microsoft (Outlook.com and Microsoft 365) · permanent error
550 5.7.244–245: HVE: external recipients not supported
HVE accounts can send only to recipients inside the organization, so messages to outside addresses are rejected.
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- Permanent (5xx)
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At a glance
- Code
- 550 5.7.244–245
- 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 5.7.244 External sending is not supported for HVE accounts.
What it means
HVE is for internal mail, such as applications sending notifications to people in the same organization, and messages to external recipients are refused. Microsoft lists two codes. 550 5.7.244 rejects the message as a whole and asks you to remove any external recipients and try again. 550 5.7.245 refuses delivery to a particular external recipient. In both cases the fix is to send only to internal addresses through HVE and use another service for external mail.
Common causes
- The message was addressed to one or more external recipients.
- An application sends both internal and external notifications through the same HVE account.
How to fix it
- 01Remove external recipients from the message and send again.
- 02Send external mail through a service built for it, such as Azure Communication Services Email.
- 03Separate internal and external notification flows in the application.
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
Further reading
All 111 Microsoft codesEvery code in the wikiPaste your own bounce