We recently have upgraded to Outlook 2007. After doing so, we have been receiving the error "The name of the security certificate is invalid or does not match the name of the site" when opening Outlook 2007. This doesn't occur on our Outlook 2003 clients.The microsoft article #940726 explains how to fix this problem. After changing the URL'sas stated in this article, the security certificate error is gone. Now Outlook 2007 prompts for credentialswhen logging in as well as the OAB doesn't sync, Out of Office does not work, and the scheduling assistant does not work. We have an Exchange 2003 & 2007 environment with the mailboxes on theExchange 2007 server. The certificate that is installed is for mail.domain.com and was made using Windows Certificate Services. Any ideas?

http://msexchangeteam.com/archive/2007/07/02/445698.aspx Stop using the self signed certs. Probably grab a SAN cert. Also, there is a reghack for outlook to ignore cert mismatches, but that's a security weakinging.

I was having the same issue and fixed the Cert is correct and not prompting. Now I just have the prompt for credentials issue. After user login is entered, everything works. Our domain is domain.local, our cert is public address xxx.DOMAIN.com. Certificate does not give error, but the user is asked for credentials upon opening and any other time it needs to reestablish connection. Machines are domain xxx.local members, and exchange is xxx.local member. Outlook shows TCP/IP connection with no retries and established. Thanks, Jason

Please note that this fix is for those with the latest upgrade to Outlook 07 which includes email fixes. It is not for those of us who haven't upgraded to 2007 and who have an older version of email such as Outlook 2003. The reason users haven't upgraded to 2007 is because they don't need to "fix it" if it's not broken, and especially since Microsoft requires having the physical CDs for upgrading, which isn't how IT works or users that have small businesses (a large portion of the market). Also, most people don't know where there physical CDs are, so having to put that CD into the computer becomes impossible, and so does upgrading. Hope this helps.

The real Outlook 2003 is in the UK which has the following URL: http://www.certforums.co.uk/forums/showthread.php?t=12593 and is overwhelmed with the response (their servers are flooded) with people that get it. Don't take my word for it. Do a search in Google and see which link (the one listed in this email) comes up. It's the UK URL.