I know that the remailer I was running wasn't the biggest kept secret, however, I made sure not to mention it to too many local people. I wonder if my sysadmin found out thru mail-logs or thru a pgp key server or somebody told him or what? I guess I'll never find out.

Why not just ask him/her ? And while you are at it, you could ask them why they developed such a policy. Though you are obviously obliged to respect it, there is no harm in asking them what their rationale is ... it would be nice to know whether the policy was adopted on purely theoretical grounds or whether they were responding to a specific pattern of misuse. I also noticed that the policy you posted made no reference to the privacy of plaintext email, or its lack thereof. david