Ken Causey wrote:

>Is anyone else getting a message like this each time they send a message
>to the list?
>
That's probably caused by your PGP signature, and the recipient not 
having your public key in his keyring.
You should probably contact him directly using non-PGP mail and ask him 
to either fix that stupid mail refusing thing or add your public key to 
his keyring.

Cheers,
Hans-Martin