Outlook users are getting “Security Alert: ….there is a problem with the site’s security certificate”
Basically it says the security certificate has expired or is not yet valid.
Found a great blog post on fixing this problem at http://www.exchangeinbox.com/article.aspx?i=114&t=1
Using that article, here’s the summary of the commands I used to fix the problem:
new-exchangecertificate (yes, to overwrite existing default SMTP certificate)
enable-exchangeCertificate -Thumbprint F17507B29FAD09B22613A64311CEE713C3A49944 -Service IIS
remove-exchangecertificate -thumbprint 5C65AAC37C9EAB4496AB88EE609EBC997B0317FB