I'm getting the following error when sending any email:

host se002.arandomserver.com []
SMTP error from remote mail server after end of data:
550 Messages should have one or no Date headers, not 2.

So I decided to disconnect my account which was set as "Send As", however I can not add it back as a send as (Outlook removed this option?). Anyways, I setup the account again as a POP account.

However, I'm still getting the error. I talked to my host and they said its an issue with outlook.com.

I should add that the email configuration works with Gmail, Thunderbird and other third-party mail clients. It's just outlook.com that's giving me a hard time.

Anyone have a fix for this one?

1 Answer 1


By the way, the above error we all get with external accounts is an incompatibility of the NEW outlook with the popular SpamExperts outgoing spam blocker that most web-hosts use. The new outlook fails to send emails VIA these connected external accounts because it fails the SpamExperts filter due to "Messages should have one or no Date headers, not 2."

outbound.mailspamprotection.com is the address of the SpamExperts service. I have already contacted them, it is NOT a fault on their side, it is the new outlook. The old outlook was passing the filter without problems.

  • Hey @foxathome, thanks for the insight. I will share this with outlook support team.
    – DomainsFeatured
    Commented Oct 11, 2016 at 20:54
  • 1
    FYI, this is definitely correct (I work on the SpamExperts filtering system mentioned here). outlook.com made some change to their system, which meant that they added a second Date: header (the RFC says that there should only be one), which was also in the wrong format (one Date: right, one wrong). Ideally, this would be something that Microsoft fix. However, in practice they take too long to do this, so the SpamExperts software was adjusted to ignore this specific problem.
    – Tony Meyer
    Commented Oct 18, 2016 at 9:43
  • Thanks for the comment Tony. I was working with Microsoft Outlook Level 3 support and showed them your thoughts. Please upvote when you get a minute. Thanks for the help. Commented Oct 21, 2016 at 13:36

Not the answer you're looking for? Browse other questions tagged or ask your own question.