[imp] Extremely weird IMAP behaviour - IMP or c-client problem?

[Eli]

I've spent about 8 hours trying to troubleshoot what is the most peculiar
problem I've ever seen.  I have an IMP install all done up (using the latest
release versions of Horde, IMP, Ingo & Turba as of yesterday) and have been
trying to figure out an IMAP problem (which sparked me to get the latest
versions and try with those) that seems to only occurr with a SmartMax
(http://www.smartmax.com) IMAP daemon.

First things first, you can check the "test.php" page for my test install
here:  http://66.165.106.121/test/horde/test.php

The install is somewhat customized - I have a few hooks, the most important
being one that operates on preauthentication to figure out if the user can
use the webmail system (it also does some neat DNS stuff to figure out their
IMAP & SMTP server).  This hook appears to be working (though for some
reason SMTP Auth isn't working right, but that's a different problem) and
have done extensive testing to pretty much rule out most (if not all) of my
customizations as the source of my problem.

Now, the problem seems to only happen when IMP tries to communicate with a
SmartMax IMAP daemon - I've tried also with an IMail and Courier-IMAP daemon
and they do not have any problems (logins work fine, all folders appear
fine, etc...).  When trying to log in/communicate with the SmartMax IMAP
daemon, it takes several login attempts before one works.  If it works, it
may arbitrarily require you to log in again after doing almost anything.
The furthest I've got is being able to click on the Mail link from the side
menu to display my Inbox and then when I click on the Folders top menu (to
admin folders) it prompts me to log in again.

I did some IMAP logging on the SmartMax server and saw IMP doing this:

19:56:06 [143] 00000000 CAPABILITY
19:56:06 [143] 00000001 LOGIN <email at example.com> "<password>"
19:56:06 [143] User email logged in.
19:56:06 [143] 00000002 CAPABILITY
19:56:06 [143] 00000003 LIST "" %
19:56:06 [143] 00000004 LSUB "" *
19:56:06 [143] 00000005 LIST "" INBOX/%
19:56:06 [143] 00000006 LIST "" INBOX/%
19:56:06 [143] 00000007 LIST "" INBOX/%
...

It seemed to go on for about a total of 1000 attempts at issuing the LIST
command before it died off and of course in the IMP interface I had to log
in again.  Subsequent attempts would not always yeild it doing the same
thing - I assume it was caching something so it didn't always do this again,
but I'm not sure.  Now, I'm no IMAP expert so I tried the command IMP was
doing to see what the output was:

0 LIST "" INBOX/%
* LIST (\NoInferiors) NIL INBOX
0 OK LIST completed.

I did the same command on the other 2 IMAP servers (IMail & Courier-IMAP)
and they did not return the same thing (in fact I believe they returned
nothing).  I don't know if this means something or not... The "NIL" part is
interesting, as is the fact that if I issue the same command but for a
different folder:

0 LIST "" Trash/%

I get the same reply "* LIST (\NoInferiors) NIL INBOX" back.  I would not be
surprised if anyone believes the SmartMax IMAP daemon being buggy - but it
won't help me since the SmartMax programmers are horribly reluctant to fix
*ANY* bug I submit to them (I honestly don't think they know how - I've
submitted about 5+ bugs to them which require fixing but nothing ever
happens).

After this, I thought maybe that PHP/c-client might be the problem.  So I
grabbed the latest c-client/imap tarball from
ftp://ftp.cac.washington.edu/imap/ and compiled that and recompiled PHP.
First thing I noticed was that from the c-client version I had used before
to what I had now, the IMAP c-client version went from "2001" to "2000" even
though I had the 2004 source code.  I tried several different ways of
compiling to see if the version # would change but no luck.  I ended up
grabbing the latest development snapshot and using that - still "2000".
During each compile I still tested to see if the IMAP problems were
happening and they were, so I was no better off now than I was before
really.

This whole problem came about after I announced to many clients that they
could use a new webmail interface (we used to have IMP 2.2 or something on a
server, and I got a new server and installed newer horde + apps).  Much
testing had gone through before announcing - but I do not know how much
testing (if any) was done communicating with a SmartMax server.  When users
started using it and reporting login problems, I first thought either too
much load for SmartMax, or something else.  I was able to rule out
everything except IMAP communication itself which is where I am at right
now.

I have not tried any development snapshots of Horde or IMP yet, but I will
if someone knows that this is a reported bug (I searched, couldn't find
anything) and has been fixed in a newer version.  If nobody has reported
anything like this before but is willing to help me troubleshoot, please let
me know - I can provide you with account logins for testing purposes so you
may see just how messed up this is!

Thanks in advance,

Eli.