Microsoft (Outlook.com and Microsoft 365) · permanent error
5.7.504: recipient address not valid
Microsoft 365 rejected the recipient address as not valid; check the address and try again.
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At a glance
- Code
- 5.7.504
- 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
5.7.504 Recipient address rejected: Access denied
What it means
Microsoft lists 5.7.504 with the text Recipient address rejected: Access denied, preceded by the address, and describes it simply as a recipient address that is not valid. It shares its wording with 550 5.4.1, which Directory-Based Edge Blocking returns for addresses missing from a tenant's directory. Microsoft's advice is to verify the recipient's address and try again. If you are sure it is right, the recipient's admin is the one who can check whether it exists in their tenant.
Common causes
- The address is mistyped.
- The address no longer exists in the destination organization.
How to fix it
- 01Verify the spelling of the address and send again.
- 02Confirm the address with the recipient by another channel.
- 03If the address is correct, ask the recipient's admin to check that it exists in their Microsoft 365 tenant.
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
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