Okay, so I've done everything listed at the following URL:
and also did fixed the registry settings that max the message limit @ 10mb in the registry of the workstation. i can only post one link, but this fix is found on google using the error message below as the search term.
and I'm still getting "Attachment size exceeds the allowable limit" on the workstation. Any ideas?
EDIT: Also, we're getting this message in Outlook immediately after you click "Open" to attach the file.
EDIT 2: Thank you for your replies. Still having the error message after several days, so assuming Active Directory should update by now, we've been all over the place so haven't had time to check it this week and long holiday break this year, so will give these a try on Monday and answer the question.