I am needing to decommission our first Exchange 2013 server in our organization. We recently migrated off of Exchange 2010. I have three servers.

2 x CAS/MBX

1 x CAS

The first server that was installed is displaying some issues and I need to decommission the unit. I have moved all mailboxes off of it. I know that when this unit went down over the weekend, even though I have the two other servers, no mail would flow in or out until it came back online. I also need to make sure my clients point to the two other CAS servers. Right now, if I fire up a new employee account and make sure their box is on the good server, outlook still connects to the first unit.

If I go through the uninstallation procedures, will exchange recognize this and move services over to the other server(s) accordingly? If not, how can I go about making these appropriate changes and then decommission this unit.

First, you need to check to which server your MX (and SPF) records point, in your public DNS. Check your send connector for Internet, and make sure that your other servers are also able to use it. Also, make sure that you redirect URLs for OWA, ECP and ActiveSync to other servers. in Exchange 2013, Outlook will not connect to the server name but to mailbox guid, so you shouldn't be experiencing these issues.

After you set this up, test your functionality with old server turned off, and then uninstall it. Exchange uninstall procedure will not let you uninstall Exchange if anything critical is left there.

OWA, ECP and ActiveSync were already going to the other servers and our public DNS points to our SPAM filtering system. We send all mail, inbound and outbound, through our SPAM filter.

If I turn off the box, nothing works except receiving mail from the outside. With that box off, I can't send internal messages, nor can I send messages out. I have my other servers associated to the send connector that routes mail to my SMART Host, which is my SPAM filter.

If I send mail out, I never see it hit the smart host.