Outlook won't send emails

Question

I keep getting this error message: "Your message wasn't delivered because the recipient's email provider rejected it."

There is no rhyme or reason to it. Emails will send to a very limited number of accounts, but I receive that message for all the rest, and they seem to have nothing in common (different emails providers, etc.). It's a personal hotmail account. Please help! I am not technically minded.

Answer 1

Thanks for posting the full NDR. The key part is that the message is blocked because it contains content identified as spam. Which means the message is being stopped by spam filtering, not because the addresses are wrong. In your headers, I can also see Content-Type: application/ms-tnef; TNEF can cause send/receive issues. I recommend using HTML or Plain Text instead for internet mail.

Send a brand-new test email from Outlook.com on the web to one outside address, with a simple subject like “test”, a one-line body, no signature, no attachment, no link, no image, and avoid replying/forwarding an older message. If that works, the problem is likely something in the original content, signature, attachment, or Rich Text formatting.

Answer 2

Hi! Could you please post a screenshot of the full undeliverable message/NDR with personal information hidden, especially the part after the error code? That message usually means the recipient’s mail server rejected the message, and it will also let you know the reason for the rejection.