Outlook continually sends emails from one address to Junk Email

[Jaxon]

I have one user in an organization whose Microsoft 365 Outlook keeps sending emails from another person in the same organization to the Junk Email folder. The email accounts are IMAP hosted by Rackspace. I have disabled automatic filtering in Outlook's Junk Email Options and added the senders email address and domain (which is the same as the recipient's) to the Safe Senders list (multiple times), but emails from the same sender keep going to the Junk Email folder. Emails from the sender don't immediately go into the Junk Email folder, but sit in the Inbox for a while before moving to Junk Email. I have tried manually moving the emails back to the Inbox. They sit in the Inbox for a while then move back to Junk Email. I have tried setting up a new profile but still have the same issue. Rackspace is set up to send spam email to the Spam folder, which appears to be working correctly, and there don't seem to be any other Rackspace settings which could cause this behavior with the Junk Email folder.

I'm completely stumped at this point. Any help will be greatly appreciated!

 

[britechguy]

Have you looked at the individual user's message rules?

I admit that this is a very long shot, but it takes mere moments and Outlook allows so many different triggers and timers that it could be something in there that's associated with the "From:" address.

 

[Jaxon]

Have you looked at the individual user's message rules?

I admit that this is a very long shot, but it takes mere moments and Outlook allows so many different triggers and timers that it could be something in there that's associated with the "From:" address.

Sorry, I meant to mention that in my original post. I previously checked the affected user's rules, and he does not have any rules set up in Outlook. Thank you for the reply.

 

[timeshifter]

So if you shut down their computer and logged in to the webmail interface on Rackspace for that account, what happens? I presume the mail doesn't move at all? -i.e. the Outlook program on the PC is doing it?

 

[callthatgirl]

Test without the signature, seen this before. Some rando link is probably causing it.