Frequently Asked Questions
10/Jul/2001
(Please send your clarifications or answers to the mailing list.)


Why "connection refused" when I check emails?

Make sure the POP3 server is running either as a daemon or via
tcpserver or inetd, for example. (If you get a "Connection
closed by foreign host" then your firewall may be stopping you.)

Why do the logs say "logged in with mailbox '/dev/null'"?

Make sure that the mailbox really exists. Make sure that it is running
with the correct UID so it has permissions to access the mailbox. This
POP3 server uses /dev/null when the mailbox does not exist or is not
readable. This is not a POP3 server problem. Make sure your mail transfer
agent (MTA) or mail delivery agent (MDA) is delivering to the correct
location. If using virtual mail support, make sure the mailbox is 
readable and writable by the defined VIRTUAL_UID.

What does "pop3/tcp server failing (looping)" mean?

If your log entry looks like:
  inetd[20921]: pop3/tcp server failing (looping), service terminated
Then your POP3 server is not broken. This means that inetd has reached
the maximum amount of servers for one minute (default is 40). To fix this,
configure your inetd entry for your POP3. Read your inetd and inetd.conf
manual pages -- search for "wait" and then "max". For example:
   pop-3  stream tcp nowait.75 root /usr/sbin/vm-pop3d vm-pop3d -i

Can I run vm-pop3d without any superuser (root) privileges?

You can run vm-pop3d without any root privilege as long as you use a
different port (such as 1100) and are able to change the group and UID.
You can run vm-pop3d via inetd as a different (non-root) user. Just make
sure that the user and group that vm-pop3d runs as has access permission
to read the passwd files, create lock files and read and update mailboxes.

What does the logged "Failed to create lockfile" mean?

This means that vm-pop3d couldn't create a lockfile in the current spool
directory. This was probably caused because your vm-pop3d did not have
write permissions for that directory. Make sure that the user or group
that your vm-pop3d runs as has permission to create a file in that
directory. (A lockfile is simply an empty file that tells other vm-pop3d
sessions that the corresponding mail box is in use; the lockfile is removed
when the session ends.)

My password is correct, but it is rejected; I receive "-ERR Bad login".
What is wrong?

Most likely, it is built to use PAM (Pluggable Authentication Modules)
support and your PAM configuration is not setup. You may need to setup
/etc/pam.conf or /etc/pam.d/vm-pop3d with the information from the
included vm-pop3d.pamd file.

Or maybe you are using IP-based support but you are trying to login
with a regular system user. Even without the realm name appended, it
figures out which passwd file to use from the IP that it was connected
to.  Your logs should tell you that it couldn't read the non-existent
passwd file.

What does "Socket closed" log message mean?

Basically, this means that the POP3 session was not properly closed.
Probably the POP3 client did not send a QUIT command. This is common
with Outlook and Outlook Express. A similar message from another POP3
server is: "-ERR POP EOF or I/O Error".

Can I use MD5 passwords instead of DES?

It has been reported that you can use MD5 passwords with Debian
GNU/Linux 2.2 "potato" using libc6 2.1.3-18. The hashed password must
be generated starting with a "$1$"; for example:
   $passwd = crypt ($ARGV[1], '$1$'.$salt);
Apparently, the crypt does the right thing, so no changes are needed
in the server.

What does "Quitting - host name not found" mean?

This usually means that no DNS or /etc/hosts is setup to map the IP
address to a real hostname. It is used for the IP-based virtual support.
(This hostname will be used for passwd file path.)

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