We are migrating from Exchange 2007 to 2013, during the co-existence phase, where is the legacy.{domain.com} namespace used? We are at the point now that we want to move all services over to the Exchange 2013 CAS servers, however... GPO settings are used to point outlook clients to mail.{domain.com} for Outlook Anywhere. If DNS is updated to point mail.{domain.com} to the Exchange 2013 servers, will there be an issue with connectivity for people still on the Exchange 2007 servers? Do these people need to point to legacy.{Domain.com} or will mail.{domain.com} proxy the connection to the legacy namespace? I would like to know if the GPO settings will interfer with the settings that Autodiscovery provide back.
I have read a bunch or articles on the approach, but I am still fuzzy on where legacy.{domain.com} comes into play.
Thanks in advance for your help.