You can download the dahlins.com certificate authority (CA) certificate from http://www.dahlins.com/certs/cacert.pem (Of course, distributing certificates this way is not terribly secure, but it is "pretty good").
The SHA1 Fingerprint of the dahlins.com certificate authority certificate is: 29:C6:C4:E5:98:78:7E:04:F1:11:32:32:D4:79:E8:3F:12:A4:B8:1B
To use this certificate in Netscape, go to Edit-)Preferences-)Security-)Certificates-)Manage Certificates, and Import this file as an Authority. Specify that it should be trusted for email.
If you would prefer not to put this in netscape, you can use openssl to verify my certificate.