Client reconnecting to Exchange 2010 after migrating to Office 365

After our first 365 migration we left the mail-server online to export more folders but had an annoying problem where after using Outlook for a while they would start trying to use the old server again as the mail server. It worked, but wasn't quite right - and eventually stopped working altogether.

The reason for this is that Outlook still looks on your local network for an auto-discover virtual directory - so if you need to keep the mail-server on be sure to remove the auto-discovery folder!

• View your current autodicover information (I tend to take a screen grab)
• Get-AutodiscoverVirtualDirectory | fl Name, Server, InternalUrl, Identity
• Remove your autodiscover info (be sure to replace SERVER with your server name)
• Remove-AutodiscoverVirtualDirectory -Identity “SERVER\Autodiscover (SBS Web Applications)”
• Alternatively, read what the folder is called, as you may need to run
• Remove-AutodiscoverVirtualDirectory -Identity "SERVER\Autodiscover (Default Web Site)"

And that should fix it!