Does Outlook continue to auto-discover account settings for already configured accounts? Can it be prevented?

I know, very old thread, but I stumbled on it. Outlook will try among other things a Root Domain query. Many Websites that have secure certificates will have a wildcard on the certificate.

So basically what happens if your website root domain and your e-mail root domain are the same, Outlook can send Autodiscovery info to your website hosting provider, and they can get fed up with it.

Use the GPO settings to disable Root Domain Query

http://support2.microsoft.com/kb/2212902

Outlook and activesync devices will autodiscover on each startup. If you leave outlook open, it should not continue to ping that URL unless there is a redirect loop going on. Use a .htaccess file to 301 redirect the link to your exchange server.

By default, it's going to look at example.com/autodiscover/autodiscover.xml and also autodiscover.example.com with same path. This works great if you don't use http://example.com for web ( no www. ) but not so well in your case. It is possible that it's not able to reach any of the autodiscover records and so it keeps retrying, so a solution may be to make sure at least one of the expected URLs works. It will check SRV records, but I believe it hits those last.