I'm part way into a migration from 2007 to 2010. I migrated the one team a few weeks ago and all worked fine and migrated several test 'user' accounts and all ok.
However have hit a strange issue which is difficult to explain so please bear with me.
We used a MDM appliance as a gateway to our Activesync just FYI - I think this is irrelevant but mentioned it anyway.
Last week one of the migrated users stopped receiving email on his iphone. Also I migrated another user last Friday who also is now not receiving any emails on his phone.
Now I've checked the logs on the MDM and can see when it connects to the original CAS(2007) it is getting redirected to the new CAS (2010) for these two users that don't work. For the users who phones do work, the connection is redirected not to the new CAS server but to the new Mailbox server.
I realise MDM should point to new CAS server but this isn't the issue as 8 of 10 of the migrated users work.
Now all the above mentioned users are in the same mailbox DB on the same new 2010 mailbox server.
Can anyone explain why connection is different on a per user basis? ie. the users that don't work get sent to one server and the ones that work get sent to another? Isn't that all dictated by the database\server settings and not on a user-basis?
Would appreciate any suggestions/ideas as to what the connection is doing. When the connection hits the CAS what exactly dictates where it is redirected because it cant be what I thought it was!
My dns is fine, all resolution works and there's no firewalling in the way. OWA works for ALL users and Outlook client works for ALL users (By ALL I mean the migrated users and those remaining on the 2007 server)
Been looking at this all day so maybe missing something obvious.