This has happened to me a couple of times; I reboot my server and attempt to connect Thunderbird (from my Ubuntu desktop) back to my Exchange mail server (on an SBS 2003 machine) and I get this message which ends in “error code -12263”.

Oh, what? You don’t know what 12263 is? Beats the fuck outta me.

A Google search yielded several problems which barely applied to my situation (most of them dealt with this error in relation to secure Web sites using https) and I found some information about a certificate problem (which actually dealt with Thunderbird).  None of the offered solutions did me any good.

However, this was all pretty good information for me.  I hopped over to my server and attempted to restart IMAP4:

• Right-click on My Computer
• Choose Manage from the context menu which appears
• Find Services and Applications on the right
• Click the + to expand Services and Applications
• Locate Services below that and click on it
• Right-click on Microsoft Exchange IMAP4
• Choose Restart from that context menu

That failed for me too.  But IMAP is dependent upon IIS Admin Service (Internet Information Services):

• Start –> Programs –> Administrative Tools –> Server Management
• Expand Advanced Management
• Expand Internet Information Services
• Right-click on [YourServerName] (local computer)
• Choose All Tasks –> Restart IIS… from the context menu

So, looks like it was useful information that other folks were experiencing problems with secure sites.

I then restarted IMAP4 again just to confirm it would restart.  After that I was able to connect to my various mail boxes from Thunderbird without issue.

Go figure.