we have a bit of a situation at one of our clients.
Case is as follows:
Exchange 2013 server on windows 2012 R2, RDS on an other Windows 2012 R2 with outlook 2007 (client couldn't afford to replace Office as well at this time).
Exchange is migrated from exchange 2007 on a Windows 2003 server.
All mailbox have been migrated and after a few weeks we removed the exchange 2007 from the coexistance.
And that's when the problems started.
No day later after we moved the Public folders to exchange 2013, recreated some connectors and de-install exchange 2007, we are getting calls from the users that that outlook is repeatedly telling that the connection to exchange was lost and and recreated. Ofcourse when they try to send an e-mail and the connection gets lost the mail gets stuck in the out-box untill outlook reconnects.
Accourding to the event logs on the remote desktop server, the connection losing and reconnecting occurse ever 2 or 3 minutes. And stops when most people go home at the end of the day. Ofcourse it starts in the morning again.
So. What we already know:
- Users are opening multiple mailboxes (their own + shared mailboxes)
- We can't turn on cache mode cause it's not supported on outlook 2007 in RDS. We tried a registry tweak to enable it anyway, but that didnt work
- We notice that one outlook session makes a lot of RPC over HTTP connections (6 for a single mailbox, 24 for someone using multiple mailboxes).
Strangest thing is. We didn't have the problem when the exchange 2007 server was still up but not in use. All outlook 2007 were already connecting through the http/rpc connection via the new exchange 2013/iis apppool.
So... what to do.
I know we can force the client to buy office 2013 for all users (VLK license) but since Outlook 2007, Exchange 2013 should work together, I am wondering if there is any limit we can tweak so there are less reconnections.
Hope someone can help.