[Postfix] 450 Sender address rejected: Domain not found
Linux - ServerThis forum is for the discussion of Linux Software used in a server related context.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
[Postfix] 450 Sender address rejected: Domain not found
I am about to migrate my mail system onto another machine. I copied everything there and this is what I started getting when I wanted to send a test mail from gmail -> my server.
Code:
May 14 15:33:18 mailserver postfix/smtpd[1688]: connect from unknown[209.85.160.44]
May 14 15:33:19 mailserver postfix/smtpd[1688]: NOQUEUE: reject: RCPT from unknown[209.85.160.44]: 450 4.1.8 <myaccount@gmail.com>: Sender address rejected: Domain not found; from=<myaccount@gmail.com> to=<peter@myserver.com> proto=ESMTP helo=<mail-pb0-f44.google.com>
May 14 15:33:19 mailserver postfix/smtpd[1688]: disconnect from unknown[209.85.160.44]
From the official postfix documentation I read that 450 code is mostly a temporary DNS error. Strange, as when I do
Quote:
dig gmail.com all
or
Quote:
host -t mx gmail.com
- everything is being resolved correctly. Below, I posted my main.cf, although the configuration is OK (as I have it on another server which is now online and accepting everything correctly). My intention is not to remove the restrictions which cause the problem for that won't resolve them. I would like to find out what causes such a behaviour? How postfix checks other domains' MX entries? Thanks for any tips in advance.
No, it's not. Maybe it is because I've got just 2 ports opened, 25 and 143?
More weird messages are coming though (I'm trying to send mails to gmail):
Code:
May 16 22:17:30 mail postfix/smtp[3835]: 1AB5EE07FF: to=<mygmail@gmail.com>,
relay=none, delay=382, delays=382/0.02/0/0, dsn=4.4.3, status=deferred (Host or domain name not found.
Name service error for name=gmail.com type=MX: Host not found, try again)
The link when you go there, says that apparently my postfix was chrooted and I needed to copy resolv.conf and services to /var/spool/postfix. Now why I used the expression "was chrooted". It is because I did not indicate a chroot installation of postfix. All I did on the new server was yum -y install postfix.
Now knowing that, and having gained some experience I would like to ask you how can I distinguish between a chrooted installation and a regular installation of postfix. Moreover, is that now a standard in Centos? I do not mind security at all, but would be nice to know what is getting installed on your system by default!
I still do not understand, why the comma is missed between check_sender_access and reject_unknown_sender_domain.
To check if the running process is chrooted you can look at the /proc/<PID>/root symlink
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.