I'm in the final stages of completing the transition from Exchange 2003 to Exchange 2010. Both still co-exist at the moment. In our environment, we do a lot of scanning to email. We do not allow relaying, so all this email is internal. Up to this weekend, we had no limit to how big the files could be (as some get very large <100MB or more>). We had an issue this weekend with some of our internal mail on the 2003 server getting hung in queue. This resulted in the deletion of the Internet connector on the 2003 server, the recreation of the routing group connectors, and the addition of a receive connector. All are at default settings, which is 10240K. I'm fine with restricting incoming mail from external sources to 10MB, but I want to be able to receive large internal emails.
Do I just create another custom receive connector for SMPT (25) and reduce the remote IP range to my internal networks, and then expand the allowed size? I just don't want to add a connector and then have my other Internet receive connector to stop working. I don't think it will, but would like to confirm with you experts that have done this before.