We are at the tail end of our co-existence migration from exchange 2007 to 2013 and have noticed recently that all external mail is flowing through our old 2007 server. Is there a way to test and see which receive/send connectors are in use when external email comes in? We can see that the mail hits our SPAM firewall, and is routed to our edge servers, then sent from the edge to our old 2007 mail server which then transfers the item to our 2013 mail server.
Another question would be do we even need to forward the mail from the SPAM firewall to the Edge or should it go directly to the mail servers?
Also, could there be some kind of edge subscription on the old server that is affecting the mail flow?
Any suggestions/help would be greatly appreciated.