Hi,
No, "well-known host names" like mail, www, ftp, news, etc. at
least _were_ a sound strategy. There's nothing wrong if your
smtpd says "EHLO mail.mehnle.net" and this is only a CNAME.
This is incorrect. The fqdn given as parameter to EHLO must be a
primary host name, not an alias:
RFC 2821, section 3.6
| - The domain name given in the EHLO command MUST BE either a primary
| host name (a domain name that resolves to an A RR) or, if the host
| has no name, an address literal as described in section 4.1.1.1.
Yes right, but I see a high number of time some bloody bad configured
servers that sends mail with incorrect HELO with legitimate mails...
Main problems with that is that some administrators set a mail server and
doesn't know a word about rfc and what is needed to have a correctly setup
mail server.
I have a long time rejected mail when HELO was not a resolvable and I get
too much legitimate mail that have being rejected....
I some "bigs" can do such setup (eg aol, msn, yahoo) then this will
_force_ so dumb mail administrators to have a correctly configured mail
server...
But you know... This is a dream...
/Xavier