Recently replaced the SSL cert on our Exchange 2010 box with a new wildcard cert. Assigned services, reconfigured all URL's for external and internal access to be identical (previous cert was a SAN cert with .local domain names and since they are no longer available we are having to change this), setup split DNS so internal and external clients all use the same DNS name for access.
Everything works as expected, with the exception of Outlook clients receiving a mismatch certificate error… it appears the server is presenting the server.domain.local FQDN to the client and with the SSL being *.domain.com it doesn't match…
I have followed all guides/articles I found ensuring that all URL's are setup properly and all point to the same external DNS name. Autodiscover internally also works and passes (we do not have it setup to autodiscover externally but Outlook anywhere does function as it should when manually configured, this has been tested)
What has me perplexed with this issue is that newly created profiles/accounts do not have this issue so it seems to be more of an Outlook profile issue rather than a server issue. I can open Outlook and use my previously configured profile and I get the SSL mismatch error.. If I create a new Outlook profile and setup my account within it, there are no SSL errors at all.
Not certain if anyone has come across this before or not but any advice/help would be greatly appreciated… while rebuilding the Outlook profile does fix the issue, with 25 – 30 users that isn't exactly something I want to have to do…. It isn't something that should have to be done…. Thanks in advance for any response/assistance.
Clay
Edit –
My issue isn't quite like the referenced Outlook Security Alert question… but more so Like this one – Outlook/Exchange certificate errors after setting clientaccessserver, etc… properties… this one seems to be almost identical to my problem… sadly it has no answer though
Best Answer
I have come across same issue while doing migration to Exchange 2013 requiring to replace SSL cert on Exchange 2010 and configure OA to enable proxying through Exchange 2013. Solution to avoid cert pop ups on desktops was to import Outlook 2013 GPO template and enable GPO for Autodiscover to ExcludeLastKnownGoodUrl.
Outlook 2013's new feature to store last known good urls and order of processing connectivity when launched is the culprit :)