and there is no requirement to do so - the only requirement is that
the hostname exists in DNS
And that is not actually true. RFC-821 Section 3.5 says:
"The sender-SMTP MUST ensure that the <domain> parameter in a HELO
command is a valid principal host domain name for the client host."
Key words... "MUST" and "for the client host" meaning FCrDNS. Since RFC
purest want to be literal, it literally *IS* a requirement to have a
valid FCrDNS for HELO FQDN.
Now comes the rub, the RFC's then say that:
"the receiver MUST NOT refuse to accept a message, even if the sender's
HELO command fails verification"
So i can see why you say its not a requirement. But it is.
If people are going to be RFC zealots then no one would be allowed to
use a RBL list for fighting spam. A spammer checks all of the boxes on
the list of requirements for a valid email, but people still choose to
block email on RBL list going against the RFC's. If you are using
spamassassign you are violating the RFC's. So im tired of hearing that
defense against common sense approaches that do not violate the RFC in
spirit.
because 2 days later you have your own customer on the phone why he
can't deliver any longer mails to you
Why so? Your customers should be using a submission port for sending
emails. That is what submission ports are for. You would not enforce any
kind of PTR, HELO or FCrDNS on a submission port because you know those
are coming from customers (residential ISP connections) *AND* you are
using SASL authentication instead. People using an IMAP/POP3 client
should not be directly connecting to a mail servers port 25 which is
where you would be enforcing FCrDNS.
frankly there is nothing wrong with the setup at all
Disagree, they are violating RFC-821 Section 3.5. Just because the RFC's
then tell receiving servers to not enforce it doesn't mean they aren't
violating the RFC's.
if you have problems with receiving mails from there it's your stubborn
setup
Your logic is the same as saying just because a city DA office makes a
policy not to prosecute shoplifters does that mean shoplifting is now
legal? And there is nothing wrong with it? Id hope people would still
follow the spirit of the law, not shoplift, consider the impacts of
their choices on the rest of the world and stop to ask, just because we
could, does it mean we should. Yes you COULD violate RFC-821 Section
3.5, the RFC police wont arrest you. But should you when its so easy not
to? What are you gaining by NOT having proper FCrDNS?
_______________________________________________
Roundcube Users mailing list
[email protected]
http://lists.roundcube.net/mailman/listinfo/users
