Virtual Users With Postfix, PostfixAdmin, Courier, Mailscanner, ClamAV On CentOS - Page 6
Queue ManagementYou might want to view the mailqueue, if some mails are still pending or so.
Time to learn something about a helper application that comes with Postfix: postsuper. Set a mail on hold:
postsuper -h MESSAGEID
Every message has its unique ID provided by Postfix when it accepts a message. If you want to address all mails in the queue use ALL.
When you delete a mail it goes like this:
postsuper -d MESSAGEIDDelete all mails in the queue:
postsuper -d ALL
Postfix daemon processes run in the background, and log problems and normal activity to the syslog daemon. The syslogd process sorts events by class and severity, and appends them to logfiles. The logging classes, levels and logfile names are usually specified in /etc/syslog.conf. At the very least you need something like:
mail.err /dev/console mail.debug /var/log/mail/maillogor
# Log all the mail messages in one place. mail.* -/var/log/mail/maillog
After changing the syslog.conf file, send a HUP signal to the syslogd process.
ps aux | grep sys
root 2585 0.0 0.0 3628 632 ? Ss Nov27 0:00 syslogd -m 0
kill –HUP 2585
IMPORTANT: many syslogd implementations will not create files. You must create files before (re)starting syslogd.
IMPORTANT: on Linux you need to put a "-" character before the pathname, e.g., -/var/log/maillog, otherwise the syslogd process will use more system resources than Postfix.
Another method is to check the postfix config files.
egrep '(reject|warning|error|fatal|panic):' /some/log/file
The first line (postfix check) causes Postfix to report file permission/ownership discrepancies.
The second line looks for problem reports from the mail software, and reports how effective the relay and junk mail access blocks are. This may produce a lot of output. You will want to apply some postprocessing to eliminate uninteresting information.
The two major log files that you should check are:
- messages (or messages.log)
- maillog - located in /var/log and/or /var/log/mail
Debugging authentication problems
Courier-authlib includes a couple of debugging tools. These can be handy if you are having problems eg auth'ing via POP3, but aren't sure if its your POP3 config that's broken or whether its actually the courier-authlib that's not working properly.
Display all accounts:
/usr/sbin/authenumeratePerform a test authentication, and show all values returned from courier-authlib:
/usr/sbin/authtest firstname.lastname@example.org somepassword
A common problem after installing the Courier authentication library is that authentication, using authtest, doesn't work. Below shows how to use courier's debugging features to pinpoint the problem.
Turn on debugging:
DEBUG_LOGIN=1 # turn on authentication debugging DEBUG_LOGIN=2 # turn on authentication debugging AND show passwords
This setting is located at the very end of the configuration file.
After changing this setting, restart the authentication daemon by running the authdaemond stop and authdaemond start commands.
At this point, all debugging output goes to syslog at level debug, which is normally not shown. You will probably need to change your /etc/syslog.conf file to be able to see these messages. If you have an existing entry which says mail.info (which means facility mail, level info or higher) then you can just change this to mail.debug. Alternatively you can add a new entry like this:
*.debug /var/log/debugDon't forget to create this file, and to send a HUP signal to syslogd to make it re-read its configuration:
kill -HUP syslogd
/usr/bin/authdaemond >filename 2>&1
Issue a manual login like listed below.
If AUTH is listed you can log in to the server. This will usually allow some things which are normally restricted, for example relaying. You will need to use your username and password in Base64.
telnet localhost 25
235 2.0.0 OK Authenticated
telnet localhost pop3
You can see if your POP3 server is working correctly. It should give back +OK Hello there. (Type quit to get back to the Linux shell.)
telnet localhost imap
a login USERNAME PASSWORD
a examine inbox
Debug POP3 over SSL
openssl s_client -connect x.x.x.x:995
(Then use same commands as in POP3 example.)
Debug IMAP over SSL
openssl s_client -connect x.x.x.x:993
(Then use same commands as in IMAP example.)
maildrop -V9 -d email@example.com
maildrop: authlib: groupid=1001
maildrop: authlib: userid=1001
maildrop: authlib: firstname.lastname@example.org, home=/var/vmail, mail=yourdomain.com/s/someone/Maildir/
maildrop: Changing to /opt/mail
<press CTRL-D here>