Hi, I realize this is probably one of the most frequently asked questions, but
I really can't figure out why this was rejected.
Apr 25 12:06:01 petra postfix-226/smtpd[592344]: NOQUEUE: reject: RCPT from mail.email.eurobank.rs
<http://mail.email.eurobank.rs/>[195.242.76.237]: 450 4.1.8 <u...@eurobank-direktna.rs
<mailto:u...@eurobank-direktna.rs>>: Sender address rejected: Domain not found; from=<obaveste...@eurobank-direktna.rs
<mailto:obaveste...@eurobank-direktna.rs>> to=<mi...@example.com <mailto:mi...@example.com>> proto=ESMTP
helo=<mail.email.eurobank-direktna.rs <http://mail.email.eurobank-direktna.rs/>>
What am I missing? eurobank-direktna.rs <http://eurobank-direktna.rs/> and
mail.email.eurobank-direktna.rs <http://mail.email.eurobank-direktna.rs/> both have
forward and reverse DNS entries.
I thought maybe it just didn't resolve properly at the time the email was
received, but it's been happening for hours.
On 25.04.23 19:02, Gerald Galster via Postfix-users wrote:
Negative dns answers may be cached but usually not for hours.
Verify that the resolver running on the postfix server can
resolve that domain because this sounds like a dns problem.
https://www.postfix.org/postconf.5.html#reject_unknown_sender_domain
Query the resolvers listed in /etc/resolv.conf directly, e.g.
dig @127.0.0.1 eurobank-direktna.rs a
dig @127.0.0.1 eurobank-direktna.rs mx
Alternatively try a public resolver in /etc/resolv.conf:
nameserver 8.8.8.8
or
nameserver 1.1.1.1
If you have any kind of spam filtering that uses DNS based lists, at postfix
or spam filter level, do NOT do this.
install full recursive DNS server for your mailserver instead.
--
Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
BSE = Mad Cow Desease ... BSA = Mad Software Producents Desease
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