We have one company that is attempting to email some of our internal users some emails with 15+ MB attachments. They are receiving an NDR concerning size restriction limitation which definitely appears to be coming from my Exchange 2010 server.
I am pulling my hair out trying to find where this is failing. There are no limits set at the global level, none at a site level, there are some on Receive Connectors but they are all set to 100 MB, and none on the individual mailbox.
What makes this even more bizarre is that I can send these same internal users an email with a large attachment from my Gmail account and they receive it fine.
The message tracking log is not showing me much of anything.
Is there any more detailed logging where I might find exactly where along the line this email is failing? Reaching a breaking point.