Recently replaced an Exchange 2010 server with 2013. Wasn’t a migration as we also changed the DC to a new domain altogether. Had to change the name to meet the new certificate rules but the inbound email address didn’t change. ASG made that easy.
The new server had been running in the background so it was a fairly fast transition. ASG held the mail during the changeover, we never skipped a beat and no customers were aware of the switch over (no un-deliverable email messages).
Thanks Comodo 8)
great to hear!
thank you for 
melih