Simon, you're right - my mistake. You need to make the old RpcClientAccessServer value unaccessable, otherwise, outlook will not use "ecWrongServer" which is what it needs to update the profile. This is correct, I have a blog article on this topic coming out soon.



Unless your blog article is going to announce that Microsoft have seen the light and decided to do something about this fiasco, it isn't really going to help a great deal.

After over 10 years of Exchange admins being able to move mailboxes to a new platform and not have to touch all the clients, they are now faced with a situation that really isn't acceptable. You have two main choices

1. Touch every client to get them to use the CAS array before the migration.

2. Take the risk and cross your fingers that autodiscover will kick in and direct clients to the new server automatically because the old one has gone away. However for some of my clients who are very risk adverse, that "risk" is too high because they cannot test it and know it will work, so are faced with having to touch clients before a migration can complete so that they "know" it will work. It also means you cannot do a staged migration, which many clients like to do, it is an all or nothing.

What we need is a way to force the Outlook "ecWrongServer" cycle to take place, perhaps with a PowerShell command, and introduced before the next version of Exchange. At the moment it isn't a huge issue, but at the end of this year the early adopters of Exchange 2010 will be coming to the end of a three year cycle and the level of migrations will start to increase. That doesn't even take in to account the new version of Exchange whenever that turns up.

Those who haven't created an RPC CAS Array (and I would say about 75% of all Exchange 2010 systems I see do not have them) will find the amount of work required for their migration will increase significantly. It will be much better to get something in place now, rather than have this major issue hit in nine to twelve months time.

Simon.

Simon Butler, Exchange MVP

Blog | Exchange Resources | In the UK? Hire Me.

