# How to check which mta / mail program is in use?

Is there a command to tell me what MTA/sendmail a unix system uses?

Thanks very much

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Are you actually on the mail server, or are you trying to figure it out remotely? –  cjc Sep 21 '12 at 12:29

[root@dev ~]# netstat -tlnp |grep :25
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      1614/sendmail


or

[root@dev ~]#  lsof -n -i :25
COMMAND   PID USER   FD   TYPE     DEVICE SIZE/OFF NODE NAME
sendmail 1614 root    4u  IPv4 1413591375      0t0  TCP 127.0.0.1:smtp (LISTEN)


That should do the trick.

If you can't access the server, telnet to port 25 on it, most servers will tell you.

[bart@dev ~]\$ telnet mail.gandi.net 25
Trying 217.70.184.11...
Connected to mail.gandi.net.
Escape character is '^]'.
220 relay4-d.mail.gandi.net ESMTP Postfix

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tried the first way and it just says "master" not "sendmail" –  Alex Sep 21 '12 at 12:47
And what doe the other options tell you? –  Bart De Vos Sep 21 '12 at 12:58
ah crap, I closed it now, i found out via google that 'master' is postfix –  Alex Sep 21 '12 at 13:03
@Alex, if you look at the /proc filesystem, you can see the command line for "master". For example, if the PID of master is 2804, then cat /proc/2804/cmdline shows /usr/libexec/postfix/master. This saves the googling, and makes the identification with postfix unambiguous. –  cjc Sep 21 '12 at 13:59