When your server is connecting to the remote MTA, it's claiming to be mprsdc01.mprs.local. RR must have a check in place to make sure the sending domain exists. Of course their machine can't resolve ...
If the Outlook error message The email system had a problem processing this message, It won’t try to deliver this message again keeps troubling you, this post may ...
Microsoft has acknowledged a new issue affecting Outlook for Microsoft 365 users and causing email-sending problems for those with too many nested folders. According to Redmond, this is likely related ...