>> You may want to suppress the SIZE information . . . . > > No, this is silly, one is better off advertising the maximum size > to avoid the vast majority unnecessary partial transmission of > overly large messages. An attacker can tie up SMTP server resources > whether the SIZE limit is known or not.
OK. > Regardless, one should not enable SMTP features one does not want to > offer to outside parties. Potentially ETRN, DSN, ... A followup question. If I suppress the advertising of an extended feature by listing it in smtpd_discard_ehlo_keywords, does that also disable the feature? Or do I have to do other things to actually turn a feature off and make it unavailable even if a client tries to issue a command (such as ETRN) that was not advertised in my EHLO response? Rich Wales ri...@richw.org
