Mac mail under Snow Leopard: SSL certificate hostname mismatch

Mac mail under Snow Leopard shows this error: "SSL certificate hostname mismatch"

We use a wildcard SSL certificate: *.his.com.
since mail.his.com is the name of the server you are connecting to, some email clients are picky and won't recognize the perfectly valid wildcard certificate..

To solve this:

Click on the checkbox next to "always trust mail.his.com when connecting to his.com"

Once you have accepted the certificate, you won't see it again.