Cannot send mail with postfix

eulaersi · 12-03-2015, 09:13 AM

I'm setting up a CentOS machine on Amazon EC2 that should be able to send me mails.

I've configured postfix so that it uses Amazon SES service. I was under the impression that everything worked.

When I restarted the EC2-instance, I cannot get mails working.

1) sudo service postfix shows that postfix is not working
-> how can I make sure that this service is always running?

2) in /var/log/maillog I notice:

Code:

Dec  3 15:07:06 ip-xx-xx-xxx-xxx postfix/cleanup[15610]: fatal: open lock file pid/unix.cleanup: cannot open file: Permission denied
Dec  3 15:07:07 ip-xx-xx-xxx-xxx postfix/master[15396]: warning: process /usr/libexec/postfix/cleanup pid 15610 exit status 1
Dec  3 15:07:07 ip-xx-xx-xxx-xxx postfix/master[15396]: warning: /usr/libexec/postfix/cleanup: bad command startup -- throttling

What can possible be wrong?

berndbausch · 12-04-2015, 08:14 PM

Centos 6 or 7?

If 6, the answer to your first question is chkconfig postfix on. If 7, systemctl enable postfix.
To start it up manually, sudo service postfix start or sudo systemctl start postfix.

Not sure what to do with your 2nd question. Does this appear when you shut the instance down or start it up? Will it go away once you solve question 1?

sneakyimp · 12-04-2015, 08:15 PM

I certainly hope that mail was sending correctly at one point. It's a crime how difficult it is to set up postfix on an EC2 instance.

How did you install postfix? Did you use a package manager? Did you compile/install from source?

I'm also wondering if maybe you fired up postfix before while you were logged in as root? This might result in postfix creating certain failes (like the pid/unix.cleanup file) with permissions that are not writable by anyone but root. In my experience (which includes some CentOS but much more Ubuntu), Postfix will run as its own user. On my Ubuntu machine where I installed using apt-get (same as yum on CentOS) then postfix runs as user postfix and I can see that in /var/lib/postfix, there appear to be a couple of files that relate to postfix operation.

eulaersi · 12-08-2015, 02:50 AM

I did use a package manager. postfix is loaded as a service. But if I do "chkconfig postfix off" and reboot, and afterwards I start postfix manually, I still get these errors.

Code:

Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/postfix-script[1511]: starting the Postfix mail system
Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/master[1512]: daemon started -- version 2.6.6, configuration /etc/postfix
Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/cleanup[1516]: fatal: open lock file pid/unix.cleanup: cannot open file: Permission denied
Dec  8 08:46:00 ip-xx-xx-xx-xx postfix/master[1512]: warning: process /usr/libexec/postfix/cleanup pid 1516 exit status 1
Dec  8 08:46:00 ip-xx-xx-xx-xx postfix/master[1512]: warning: /usr/libexec/postfix/cleanup: bad command startup -- throttling

berndbausch · 12-08-2015, 03:03 AM

Quote:

Originally Posted by eulaersi

I did use a package manager. postfix is loaded as a service. But if I do "chkconfig postfix off" and reboot, and afterwards I start postfix manually, I still get these errors.

Code:

Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/postfix-script[1511]: starting the Postfix mail system
Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/master[1512]: daemon started -- version 2.6.6, configuration /etc/postfix
Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/cleanup[1516]: fatal: open lock file pid/unix.cleanup: cannot open file: Permission denied
Dec  8 08:46:00 ip-xx-xx-xx-xx postfix/master[1512]: warning: process /usr/libexec/postfix/cleanup pid 1516 exit status 1
Dec  8 08:46:00 ip-xx-xx-xx-xx postfix/master[1512]: warning: /usr/libexec/postfix/cleanup: bad command startup -- throttling

Searching the web for pid/unix.cleanup permission denied indicates that this might be an SELinux problem. On my system, unix.cleanup looks like this:

Code:

$ ls -Z /var/spool/postfix/pid
-rw-------. root root system_u:object_r:postfix_var_run_t:s0 master.pid
-rw-------. root root system_u:object_r:postfix_var_run_t:s0 unix.cleanup

You might want to check. Use restorecon to fix it if necessary.

For a quick check, you can temporarily set SELinux to permissive (setenforce permissive) and try restarting postfix.

sneakyimp · 12-08-2015, 11:24 AM

Quote:

Originally Posted by eulaersi

I did use a package manager. postfix is loaded as a service. But if I do "chkconfig postfix off" and reboot, and afterwards I start postfix manually, I still get these errors.

Code:

Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/postfix-script[1511]: starting the Postfix mail system
Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/master[1512]: daemon started -- version 2.6.6, configuration /etc/postfix
Dec  8 08:45:59 ip-xx-xx-xx-xx postfix/cleanup[1516]: fatal: open lock file pid/unix.cleanup: cannot open file: Permission denied
Dec  8 08:46:00 ip-xx-xx-xx-xx postfix/master[1512]: warning: process /usr/libexec/postfix/cleanup pid 1516 exit status 1
Dec  8 08:46:00 ip-xx-xx-xx-xx postfix/master[1512]: warning: /usr/libexec/postfix/cleanup: bad command startup -- throttling

How did you start postfix? Have you checked the permissions on the file pid/unix.cleanup?

eulaersi · 12-09-2015, 07:27 AM

Tx for the reply. I'm almost there.

Mails are being sent when I set:

Code:

sudo setenforce 0

How should I solve this? I have no experience with SELinux.

Code:

$ ls -Z /var/spool/postfix/pid
-rw-------. root root unconfined_u:object_r:postfix_var_run_t:s0 master.pid
-rw-------. root root unconfined_u:object_r:var_run_t:s0 unix.bounce
-rw-------. root root unconfined_u:object_r:var_run_t:s0 unix.cleanup
-rw-------. root root unconfined_u:object_r:var_run_t:s0 unix.defer
-rw-------. root root unconfined_u:object_r:var_run_t:s0 unix.error
-rw-------. root root unconfined_u:object_r:var_run_t:s0 unix.local
-rw-------. root root unconfined_u:object_r:var_run_t:s0 unix.smtp
-rw-------. root root unconfined_u:object_r:var_run_t:s0 unix.trace

berndbausch · 12-09-2015, 07:59 AM

var_run_t is wrong. This should fix it:

Code:

cd /var/spool/postfix/pid
chcon -t postfix_var_run_t *

The chcon command changes the file context, -t only changes the type; i.e. the part that ends in _t.

Since there might be other files with the wrong context, you can also do this:

Code:

restorecon -irv /var/spool/postfix

This will set the correct type for all files under /var/spool/postfix. -i ignores files that aren't there (otherwise, I presume, error messages might be issued), -r means recursive, and -v verbose.

eulaersi · 12-10-2015, 03:39 AM

Tx for your replies.

[SOLVED]