POP Server Setup Under MkLinux

This document describes how to build and install the qpopper distribution to provide a POP mail server on your MkLinux host. These instructions work for MkLinux DR1 or DR2. However:

• If you are running DR1, you may find it helpful to see my MkLinux procmail notes for background, noting particularly the stuff about the necessity of mail program permissions being set to the mail group.
• If you are running DR2, you may find it helpful to see my notes on mail setup preliminaries with respect to mail spool directory permissions.

Get the qpopper distribution. It's available from QUALCOMM at ftp://ftp.qualcomm.com/eudora/servers/unix/popper/. The distribution I used is for qpopper 2.2.

Read doc/README.Berkeley for general background on what you're trying to do (but ignore the part about getting the distribution from Berkeley).

Check /etc/services. It should have a line like the one below; if it doesn't, add one:

    pop3		110/tcp		# POP version 3

Check /etc/inetd.conf. It should have a line like the one below; if it doesn't, add one:

    pop3    stream  tcp     nowait  root    /usr/sbin/tcpd  /usr/sbin/in.pop3d

Before you can compile the pop server, you should make a few changes to the make.linux and popper.h files.

Modify make.linux to change each instance of -ldbm to -lgdbm (MkLinux uses the GNU DBM library).

The popper.h file defines where to look for the mail spool directory and sendmail. As distributed, the LINUX case will look in the wrong places (/usr/spool/mail and /usr/lib/sendmail rather than /var/spool/mail and /usr/sbin/sendmail), so find the line that says:

    #if defined(OSF1) || defined(AIX)

    #if defined(OSF1) || defined(AIX) || (defined(LINUX) && defined(PPC))

Compile popper (you need not be root to do this):

    # make linux

That command builds popper.linux and popauth.

Install popper (you must be root for this):

    # cp popper.linux /usr/sbin/in.pop3d
    # chgrp mail /usr/sbin/in.pop3d
    # chmod 2755 /usr/sbin/in.pop3d

I don't know what popauth is for so I didn't install it.

Then either kill and restart inetd, or send it a kill -HUP to tell it to reconfigure.

Test popper by telnetting to your local pop port; you should see something like the following:

    # telnet self pop3
    Trying 127.0.0.1...
    Connected to boa.snake.net.
    Escape character is '^]'.
    +OK QPOP (version 2.2) at boa starting.  <2437.837809045@boa.snake.net>

Type "quit" and hit RETURN, and you should see:

    +OK Pop server at boa.snake.net signing off.
    Connection closed by foreign host.

Now you're ready to serve POP mail clients.