Identifying which MTA is running

Question

I dont have knowledge on linux and how can i know which mail server is running on my linux box? Postfix/Exim? Btw Didn't found postfix folder in etc/, where can i find master.cf? .Any idea for modify cPPOP?

Answer 1

For your second question, use locate to find master.cf

updatedb
locate master.cf

Answer 2

Easiest way might be to get the PID of what's listening on port 25:

 # lsof -i :25
 COMMAND  PID USER   FD   TYPE DEVICE SIZE NODE NAME
 master  5664 root   12u  IPv4  13732       TCP *:smtp (LISTEN)

Then find out what that process is:

 # ps p 5664
 PID TTY      STAT   TIME COMMAND
 5664 ?        Ss     0:12 /usr/lib/postfix/master

And I'm running postfix. For sendmail, it looks like this:

 # lsof -i :25
 COMMAND   PID USER   FD   TYPE DEVICE SIZE NODE NAME
 sendmail 3445 root    4u  IPv4  12922       TCP localhost.localdomain:smtp (LISTEN)

Edit

Postfix config is under /etc/postfix

Answer 3

most mail servers will identify themselves

justin@bert ~ % telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 xxxx ESMTP Exim 4.69 Sat, 09 Jan 2010 15:08:05 -0500