Self signed cert authorization

[Phillip Susi]

I've been trying to convince git send-email to connect to my personal
smtp server without success.  It keeps complaining that the cert is
self-signed.  I thought all I had to do was add the cert to
/etc/ssl/certs and that should fix it, but it doesn't.  Even without
doing this, and using -verify_return_error, openssl s_client does not
refuse to connect to the server.  Why is this and what else do I have to
do to convince the system that this self signed cert is OK?