Why does dccm or dccifd complain about “incompatible whitelists”?
There are several points during an SMTP transaction when an SMTP server can reject a mail message. Early points are when the SMTP client specifies the recipients of the mail message. The last point is after the entire message has been received by the SMTP server. Spam filters that check mail message bodies must wait until that last point. The SMTP protocol does not allow an SMTP server to reject the mail message for only some recipients. The SMTP server must tell the SMTP client that the message has been accepted for all or rejected for recipients. This is a problem when the recipients of a single mail message have differing DCC thresholds or other parameters in their individual whitelist files that require that the mail message be delivered to some mailboxes but rejected for other mailboxes. The DCC client programs solve this conflict in one of two ways. One is telling the SMTP client that the mail message has been accepted for all recipients and then discarding instead of delivering
There are several points during an SMTP transaction when an SMTP server can reject a mail message. Early points are when the SMTP client specifies the recipients of the mail message. The last point is after the entire message has been received by the SMTP server. Spam filters that check mail message bodies must wait until that last point. The SMTP protocol does not allow an SMTP server to reject the mail message for only some recipients. The SMTP server must tell the SMTP client that the message has been accepted for all or rejected for recipients. This is a problem when the recipients of a single mail message have differing DCC thresholds or other parameters in their individual whitelist files that require that the mail message be delivered to some mailboxes but rejected for other mailboxes. The DCC client programs solve this conflict in one of two ways. One is telling the SMTP client that the mail message has been accepted for all recipients and then discarding instead of delivering
