David MacQuigg wrote: > > Forget about DKIM. What if there is some other reason to abort, like > the payload is too large? We cannot just continue receiving data > forever. Is there a "permissible" way within SMTP to abort during > data, or should I just ignore these ambiguous requirements, and > either: 1) Send a TCP reset, or 2) Let the transmitter hang. I would just continue accepting the message, and throw away the data, then give a 'message too big' error at the end.
I suppose you could try to be clever and do a grey-listing-style thing of recording the IP address, sender & recipient, and dropping the connection, then when the retry is done, reject the message before the data is sent - but I wouldn't be too confident about the reliability of that. -- Paul Smith VPOP3 - POP3/SMTP/IMAP4/Webmail Email server for Windows
