On 2024-01-31 at 10:12:06 UTC-0500 (Wed, 31 Jan 2024 16:12:06 +0100)
Matus UHLAR - fantomas via Postfix-users <uh...@fantomas.sk>
is rumored to have said:
On 30.01.24 20:20, Israel britto via Postfix-users wrote:
hello, I'm having a problem with spamhaus that I don't know how to
solve.
Today I have 1 domain that uses 2 exclusive IPs 1.1.1.1 and 2.2.2.2
The PTR and rDNS entries are correctly configured:
1.1.1.1 > a1.domain.com
2.2.2.2 > a2.domain.com
a1.domain.com -> 1.1.1.1
a2.domain.com -> 2.2.2.2
My Postfix is behind a load balance, which performs round-robin
balancing between these 2 IPs, however, my server is configured
with the helo -> xpto.com.br
That's almost certainly wrong. The HELO argument should be the
resolvable primary name associated with the actual client IP as it
connects to the server. In this case, that would be the
outward-facing IP of the load balancer.
# host xpto.com.br
xpto.com.br has address 186.202.157.79
xpto.com.br mail is handled by 20 mx.jk.locaweb.com.br.
xpto.com.br mail is handled by 10 mx.core.locaweb.com.br.
xpto.com.br mail is handled by 20 mx.a.locaweb.com.br.
xpto.com.br mail is handled by 20 mx.b.locaweb.com.br.
# host 186.202.157.79
Host 79.157.202.186.in-addr.arpa. not found: 3(NXDOMAIN)
On 31.01.24 09:43, Bill Cole via Postfix-users wrote:
So if your load balancer isn't at 186.202.157.79, the hosts behind it
should not be announcing themselves as xpto.com.br.
how did you get to this? xpto.com.br exists and has addres, so
there's no reason why it could not be used in HELO.
The purpose of HELO is identification of the client system to receiving
systems. A HELO name that authoritatively resolves to an IP unrelated to
the client IP is a confusion and confounding of that purpose. It should
not be done. (I use 'should' here in the secular sense, not its tight
RFC meaning)
--
Bill Cole
b...@scconsult.com or billc...@apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Not Currently Available For Hire
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