From: "Brian Tillman"

|
| In order to reply to an encrypted message, the replier must have a copy of
| your public key if they want the response encrypted as well. In other
| words, you must have sent them a digitally-signed message first before
| sending them the encrypted message. Did you do that?

Or... pull the certificate from a LDAP server.

--
Dave
http://www.claymania.com/removal-trojan-adware.html
http://www.ik-cs.com/got-a-virus.htm