NAME
courierpop3d - The Courier POP3 server
SYNOPSIS
/usr/sbin/couriertcpd {-nodnslookup} {-stderr=syslog} {110}
{/usr/lib/courier/courier/courierpop3login}
[modules...]
{/usr/lib/courier/courier/courierpop3d}
{./Maildir}
DESCRIPTION
This is a simple POP3 server for Maildirs.
Note
The couriertcpd, courierpop3login, and courierpop3d modules may be
installed elsewhere than indicated here.
courierpop3login is usually started by couriertcpd. It already expects
that a POP3 client is connected to standard input and output,
presumably via a network socket. courierpop3login reads the POP3
userid and password, then runs the authentication modules. The
remaining arguments are passed along as arguments to modules.
modules is one or more authentication modules (see the authlib(7)[1]
manual page).
Each authentication modules runs the program specified by its first
argument, allowing the authentication modules to be chained. The last
program in the chain is courierpop3d , which provides the actual POP3
service. In accordance with the authentication protocol, as described
in authlib(7)[1] courierpop3d reads file descriptor 3 to see if the
userid/password has been succesfully validated. If not, courierpop3d
terminates.
Otherwise, courierpop3d expects to be already running under the
appropriate user and group id, with its current directory set to the
account´s home directory.
The first order of business is to find the account´s Maildir. If the
environment variable MAILDIR is set, that´s where we go. That should be
the pathname to the account´s Maildir. The environment variable MAILDIR
may be set by the authentication module. If MAILDIR is not set,
courierpop3d uses its first argument. Usually, the default maildir is
$HOME/Maildir, therefore the first argument to courierpop3d is
"./Maildir".
SEE ALSO
authlib(7)[1], userdb(8)[2].
NOTES
1. authlib(7)
[set $man.base.url.for.relative.links]/authlib.html
2. userdb(8)
[set $man.base.url.for.relative.links]/userdb.html