Exchange 2007 to 2013 Mail Flow Issues w Distro Goups

I am currently in the middle of a 2007 to 2013 migration.  I am in the process of migrating mailboxes.  I have about 60 of 200 complete.  I have also replicated the public folders.  I have 3rd party applications that email notifications like Barracuda appliances, Backup Exec, etc.  I have changed these applications to use the 2013 serer to replay the mail.  If I leave the email configured to send to a distribution group the mail never gets delivered, but if I change the distro group to an individual, then the mail flows through.

For example, I am in the distro group itgroup@xxx.com, and that has always been where Backup Exec sends emails.  Once I changed the IP to 2013 server the emails stopped.  I thought it was my receive connector, but after a while I decided to change the email address from that group to just me and it works...... Same with the Barracuda..... We have a custom CRM that emails reports every morning to "C" levels and ALL of those  are not functioning....

These same distro groups that do NOT work through relay, DO work when being sent from users......

PLEASE HELP!!