dovecot - Sep 2004 - Workaround for outlook UIDL handling bug ??

Scenario: Using Dovecot 0.99.10.9 as pop3 server.
With delete on retrival off.

clients: outlook*

Problem: Everytihng work perfectly, except that outlooks keeps 
re-downloading SOME mail over and over. Though it already got them.
No obvious pattern which, but only a small percentage.

First of I looked at dovecots UIDLs.
Initialy I thought it's broken (see my previous thread) 
Sorry for even thinking that, it's ok, my bad :)
Rather, outlooks UIDL handling seems to be very broken :(

But I think I found an easy workaround.

Dovecots UIDLS seem to be

timestamp.message#

eg.

1 1093990148.1
2 1093990148.2
3 1093990148.3
4 1093990148.4
5 1093990148.5
6 1093990148.6
7 1093990148.7
8 1093990148.8
9 1093990148.9
10 1093990148.10
11 1093990148.11
12 1093990148.12

The problems started with #10

-> Asumption: outlook falsy only takes a fixed numbers of chars to hold the
UIDL, the rest ist ignored. Perhaps only the first 13 or so.

What I did is reversing the order in UIDL generation.
Instead of

timestamp.message# ->
message#.timestamp.

Seems to work perfectly.

Well, a bit too early too tell if it really works.
Need to wait a couple of days and see if the problem re-appears or not.

The only thing I'm 100% sure is that outlooks UIDL handling is broken.

BTW: very nice source code.
Very easy to follow, took me 5 minutes to find the correct .c and routine.

In /pop3/command.c, 
list_uids() all I changed is

... mail->seq, client->uidvality, mail->uid to
 mail->seq, mail->uid, client->uidvality.
(2 times)

If anyone is interested, I'll keep you informed if the problem is really
gone with this mini-patch.

On 2.9.2004, at 21:50, Nikolaus Gerstmayr wrote:
> Scenario: Using Dovecot 0.99.10.9 as pop3 server.
> With delete on retrival off.
>
> clients: outlook*
..

http://support.microsoft.com/default.aspx?scid=kb;EN-US;872839

Is it this problem? Maybe just try to get people to install SP1?

I've been thinking about making the pop3 UID format configurable, but I 
can't anymore change the default.
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> On 2.9.2004, at 21:50, Nikolaus Gerstmayr wrote:
> 
> > Scenario: Using Dovecot 0.99.10.9 as pop3 server.
> > With delete on retrival off.
> >
> > clients: outlook*
> ..
> 
> http://support.microsoft.com/default.aspx?scid=kb;EN-US;872839
> 
> Is it this problem? Maybe just try to get people to install SP1?
> 
> I've been thinking about making the pop3 UID format configurable, but I
> can't anymore change the default.
> 
Unfortunatly, SP1 doesn't help.
I read 872839 too, it gave me 5 minutes of hope, not not more :(

We had a mixture of outlook 2003's with Sp1 and without it, and a couple of
outlook express 6.x's

ALL had the same problem with the SAME mails being redownlaoded all over :(
Seems all microsoft mail clients share the same problematic UIDL code.
Updated all outlook 2003's to SP1, didn't help either.

Found this in meantime:
http://www.smartertools.com/Products/SmarterMail/ReleaseNotes.aspx

Unfortunatly it doesnt tell WHATS wrong with 
outlooks POP3 UIDL interpretation. Just that there is something wrong.

If you have something like
# values: default, yet_another_outlookbug_workaround, ...
#UIDL_SHEME default 
 
it shouldnt be a big problem.
if you can leave the old UIDL generation and its default.
and warn what happens if you switch it.

Again, I cant be 100% sure yet if my attempt to workaround that problem
really helps. Time of observation too short. 

But looks good so far.

BTW: of course I'd prefer to kick the god damn outlook's and/or switch
to
IMAP, 
but unfortunately I'm not allowed to do that :(((