At 02:38 PM 10/2/2003, Brad Knowles wrote:
AMTP does not allow a sender that is "not MPC-enabled". The MPC argument in the MAIL command is REQUIRED (section 4.4.3).If the sender is not MPC-enabled, you might end up blacklisting your backup MX.Do you mean "senders that ignore the MPC values in the EHLO response"? They will get a 550 later in the conversation. And they risk getting added to a CRL.