Tony Finch wrote:
Under the 'current' way yes, but if it is changed so that the EHLO
parameter must correspond to the IP address of the sending host, then it
won't work, and I can't think of anything which would make it work.
If the sender's EHLO host name isn't correctly set up in the DNS then the
postmaster has set up SBS wrong.
So, how would YOU set it up, given the (common) situation I described
(SBS Exchange connecting through a NAT router on a dynamic IP address)?
The only 'correct' ways I can come up with are to use the internal IP
address literal, or (if the SBS owner is a techie) to have something
like 'company.dyndns.org'. The first of these is totally useless to
anything else, and the second is arguably less useful than the
technically incorrect 'company.com' or 'mail.company.com' (because there
is no DNS record pointing those names back at the dynamic IP address)
VPOP3 - POP3/SMTP/IMAP4/Webmail Email server for Windows