Alex van den Bogaerdt wrote: > >> I would argue that 'EHLO >> mailserver.domain.com' is more useful than 'EHLO [192.168.1.1]' even >> though the former is incorrect, and the latter correct (according to RFC >> 5321) with dynamic IP/NAT. > > IMHO 192.168.1.1 is not an internet IP address. And that is a > requirement. > I'm sorry, but that can't be the case.
Otherwise, how does Thunderbird send mail to a local mail server on a private network? It can't, because it hasn't got an Internet host name, or an Internet IP address, so can't issue a valid EHLO command. Similarly, how does ANY SMTP client behind a NAT router with dynamic IP (ie pretty much any home user) send a message anywhere? If what you say is the case, then that is cutting off half the world from the SMTP network! As far as I can see RFC 5321 doesn't say it has to be a routable IP address to be used in an address literal. As far as I am aware, RFC 4409 doesn't relax the requirements of RFC 2821/5321 for the EHLO parameter, so 'use message submission' is not the answer. -- Paul Smith VPOP3 - POP3/SMTP/IMAP4/Webmail Email server for Windows
