Is it possible to have a hybrid O365 Exchange Online with on-premise 2007 and 2010 Exchange?
Is it better to migrate mailboxes to Exchange 2010 before going hybrid?
I know there's Exchange 2013, but I don't know if it would be a good idea to add Exchange 2013 into the mix when I've already got 2007 and 2010.
There is also no high availability in the current Exchange environment and I'm very tight on space that poses a problem.
The idea is get about 2 TB of mailboxes from Exchange 2007 to Exchange Online, either directly from 2007 (1 migration) or from 2007 to 2010 to Exchange Online (2 migrations?)