For the past month, I have been hearing from users that they are not receiving some of their attachments. After looking into the issue, I have found a couple of commonalities between the messages that we are having problems with... Those commonalities are...
- All the messages have been coming from people who are using the Apple Mail client. Although, not all of the message coming from Apple Mail clients are having the issue. It seems that the only ones that we are having issues with are those messages that have inline attachments.
- We can see the attachements in OWA, Outlook on the MAC, or if we forward the message to external servers like gmail or hotmail.
- The messages have the PR_ATTACHMENT_HIDDEN set to true.
- So far, the missing files have only been PDF attachments.
I have found a bunch of fixes, but none that seem to have fixed my issue. I have tried setting theShowInlineAttachments to true on our HUB servers. I have created a transport rule that rewrites theContent-Type. I have made regedit changes on the clients, setting
Level1Remove to .pdf. The Exchange servers are running Exchange 2010 SP1 rollup 3.