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We need to accept email from a server that sends out using a non-existing domain. That server is not under my control.

In my I have

smtpd_client_restrictions       = permit_mynetworks,

in /etc/postfix/access I have

<server's ip>                 OK         OK

However, when I recieve messages from that server in my logs I see:

Jul 26 10:30:07 mail3 postfix/smtpd[24044]: NOQUEUE: reject: RCPT from[ip address]: 554 5.1.8 <>: Sender address rejected: Domain not found; from=<> to=<> proto=ESMTP helo=<>

As another workaround I tried to manually hardcode this hostname:ip into my /etc/hosts, but that makes no difference.

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You shall not fix other people's failures. Will you always configure your server when someone else is not capable to administer their system? – mailq Jul 28 '12 at 22:33
up vote 3 down vote accepted

In /etc/postfix/, place the server's IP address in mynetworks.

Example (where the IP addres is

mynetworks = [::ffff:]/104 [::1]/128
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Yup, adding that server's IP to mynetworks resolved this problem. Should I keep other config changes that I made above or is mynetworks entry sufficient for everything? – Mxx Jul 26 '12 at 19:27
The mynetworks change is all you need. It's not necessary to put the IP address in /etc/postfix/access. – Michael Hampton Jul 26 '12 at 19:38
Under the right circumstances you do indeed need an access check in smtpd_sender_restrictions. It depends upon whether you have "permit_mynetworks" in smtpd_sender_restrictions and whether it comes before or after other checks. – datn Mar 6 at 23:58

Right now, probably:

~ $ sudo postconf smtpd_sender_restrictions
smtpd_sender_restrictions = reject_unknown_sender_domain

Should be?

~ $ sudo postconf smtpd_sender_restrictions
smtpd_sender_restrictions = check_sender_access reject_unknown_sender_domain

option set in
You'll need to postalias /etc/postfix/access if you haven't already.

Also, chastise the sender for not owning the domain they're sending from (or not having had created the appropriate subdomain).

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Before I resorted to modifying our mail config I fought long and hard with them to fix this problem on their end..Alas here I am. :( – Mxx Jul 26 '12 at 17:36

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