I have this problem and I am finding answers to it, but i do not think that it would work in my environment.Overview:When Outlook 2007 is opened, you get the certificate error that the names do not match.Org overview:We use OWA and ActiveSync. External name is owa.company.com. The fqdn of the CAS server is exchange.company.netI have the owa.company.com certificate installed on the CAS and it is securing IIS and I also have a certificate for the CAS server securing IMAP, POP and SMTP. All certificates are from a 3rd party.E-mail addresses are user@company.com and not user@company.netHow do I resolve this issue in this environment without breaking OWA and ActiveSync?

Check out this link: http://blog.shijaz.com/2008/04/certficate-name-mismatch-in-outlook.htmlIt should help.BP

Hi,I hope below article can help you fix out this issue:http://support.microsoft.com/?kbid=940726ThanksAllen

I tried that, but it did not work. The user still gets the certificate for owa.company.com that says it does not match the servers name. The server is exchange01.company.netAny advice?

Hi,Now please run test-outlookwebservices |fl command in EMS, then post the information on the forum.Furthermore, please run get-exchangecertificate |fl, and paste the information here.ThanksAllen

Have you added your LAN/AD FQDN to the certificate? Is it a domain you do not own externally? Is it a legitimate domain name on the Internet?