Steve Lindemann a écrit :
> Searched docs and archives and I'm not seeing it...
> (postconf -n at end)
>
> Situation:
>
> changed config to:
> smtpd_helo_required = yes
> smtpd_helo_restrictions = permit_mynetworks,
> reject_invalid_helo_hostname, reject_unknown_helo_hostname
>
> This causes legitimate email servers to be rejected (with a 450) and
> apparently most or all where m$ exchange servers. Of course they think
> the problem is on my end.
>
reject_unknown_helo_hostname is known to block "legitimate" mail, mostly
from misconfigured sites (but it will defer mail in case of DNS problems
even if the other side is well configured).
> changed config back to:
> smtpd_helo_required = yes
> smtpd_helo_restrictions = permit_mynetworks
> and the problem "went away"
>
No reason to remove all the checks. you can use:
smtpd_helo_restrictions =
reject_invalid_helo_hostname
reject_non_fqdn_helo_hostname
you can also use check_helo_access to reject some "spammy" helos. for
example:
localhost REJECT Invalid Helo
unreachable REJECT Invalid Helo
.localhost REJECT Invalid Helo
.arpa REJECT Invalid Helo
.example REJECT Invalid Helo
.example.com REJECT Invalid Helo
.example.org REJECT Invalid Helo
.example.net REJECT Invalid Helo
.invalid REJECT Invalid Helo
.test REJECT Invalid Helo
.root REJECT Invalid Helo
.local REJECT Invalid Helo
.lokaal REJECT Invalid Helo
.lan REJECT Invalid Helo
.localdomain REJECT Invalid Helo
.home REJECT Invalid Helo
.domain REJECT Invalid Helo
.private REJECT Invalid Helo
.adsl REJECT Invalid Helo
.inv REJECT Invalid Helo
.firewall REJECT Invalid Helo
.kornet REJECT Invalid Helo
.belkin REJECT Invalid Helo
.speedportw700v REJECT Invalid Helo
> Questions:
>
> 1) Is the problem really on my end with that config?
it's on the other end, but since many servers accept mail from them, the
problem is passed to you (the common "but we have no problem with other
servers". sigh).
> 2) If it is, how can I do better?
see above.
> 3) If it isn't, any suggestions for what to tell the exchange sys admins
> to fix on their end?
>
if you have the courage, motivation and resources to educate the
universe, then good luck.
> [snip]
