[imp] Imap stores messages in mbox file

[C. R. Oldham]

Greetings,

It's not really a good idea to combine the UW-IMAP and qpopper.  If at all
possible you should use the pop3 daemon that comes with the UW kit, or restrict
your users to IMAP only.

The documented behavior of the UW imapd is to move messages from
/var/spool/mail to the mbox file at imap login time.  Mark Crispin (author of
the kit) has good reasons for doing this.  There are many ways around it,
though.  Here are three:

1. Use the UW pop3 daemon.
2. Restrict your users to IMAP only
3. Install a separate mail delivery agent that will deliver incoming email
automatically to the mbox file.  Then point qpopper at the mbox file as it's
default INBOX.  Imapd will not move the messages anymore (they were already
moved).

However the biggest thing you have to worry about is concurrent mailbox locks.
The Unix mbox format cannot support multiple connections to it.  The UW imapd's
default behavior when it detects lock confusion is to simply die off to avoid
corrupting a mailbox.  Imagine, if you will, a user logging into get email with
POP3 and Netscape.  User does not close Netscape.  User goes home and tries to
check email with IMP.  Wham, concurrent mailbox access.

If you use #1 or #2 in combination with dmail (the MDA that uses the IMAP
library) you can switch to the MBX format as the default mailbox format.  MBX
does support multiple connections.

Gregory Yerxa wrote:

> I have the same issue with identical software installed.  To this point I
> haven't rolled out my installation to a production network yet so it hasn't
> been addressed.  I would also love to figure this one out.

> From: "Clavier Matthieu" <clavier@coria.fr>
> [...]

> > Users can use either imapd or qpopper on the same server.
> > Everything works nice except that some people, after reading their mails
> > through IMP cannot retrieve messages with their pop client. Messages
> > read by IMP are transferred in file called mbox under their home
> > directory.

--
  / C. R. (Charles) Oldham | NCA Commission on Schools    \
 / Director of Technology  | Arizona State University      \
/ cro@nca.asu.edu          | V:480-965-8703  F:480-965-9423 \