Here's a really quick background -

We just performed a full migration from Exchange 2007 to Exchange 2013. We ran them together in a coexistence environment while we transferred all the mailboxes over. At this point, all mail is flowing through the Exchange 2013 sever (at least we think so).

The next step in our process was to simply turn off the Exchange 2007 server to see if everything functions the way it should. Once it was off, all mail was still able to be sent and received from any external or internal source (we ran into some problems with AOL and reverse DNS lookups, but that's fixed now).

Then, we started to receive complaints that Outlook was taking too long to update folders when first launched. Since this was never a problem with Exchange 2007, we simply thought exchange 2013 just required more resources and bandwidth. After giving it more, we were still receiving this complaint. Clients are saying that it takes up to 10 min before it updates. But once it does update, everything works great from that point on.

We decided to turn the 2007 server back on to see if it helped the situation. Once on, everything updates almost instantly. I went back through all the deployment steps and checked all the settings -- everything looks correct. For the life of me and google, I cannot figure out why the mailboxes even KNOW that there's another exchange server -- or how to fix this.

Could it be simply that I need to completely remove Exchange 2007 from our environment? or is there a setting somewhere that's still pointing to the old server for just the initial update?

PLEASE HELP!

Thanks!

Hi,

Acorrding to your description,I recommend you try the following method to troubleshoot the issue:

1.Please create a new test user ,and then check the new mailbox if has the same issue.

2.Please recreate outlook profile and check the result.

3.Please use the online mode.

4.Please use the following command to open the outlook:

outlook.exe /cleanprofile

Hope it helps you!

Thanks.