For those who use SSL for email, you may find interesting a recent enhancement to server certificates from Thawte, the addition of client capabilities as well as server.

By popular demand (and I know I was one of those demanding it), the company has decided to cut a break to those who are using the same certificate for incoming and outgoing email service. In the grand scheme, it's not a huge deal, but it will mean that when your mail server connects to another SSL- enabled mail server, each side will be able to completely verify its identity. In the past, a server with a valid server certificate still showed up as unverified in the log of another server when connecting as a client.

Thanks, Thawte.