[Dovecot] great disappearing email mystery

[John and Catherine Allen]

dhottinger at harrisonburg.k12.va.us wrote:
> Have there been any issues with dovecot and using outlook express (imap) 
> as an email client?  I have had a couple of users come up with random 
> missing emails.  Im trying to figure out if it is user error, or 
> something wacky in my mailserver.   I cant find anything telling in 
> maillog files or my messages.  Dovecot version is 1.0.3.  Its ok to 
> reply to me, I get list messages digest.
> 

Dwayne,

I've seen a lot of answers to your question which talked 
about Outlook, not Outlook Express. As far as I know, 
Outlook Express is a completely different piece of software.

I've been using Outlook Express and Thunderbird as IMAP 
clients for years (more than 8 years in the case of Outlook 
Express) and hundreds of thousands of emails, and there's 
never been any systematic problem with either of these 
applications used as IMAP clients.

Occasional apparent "missing" emails were caused by:
- The local Outlook Express mail file getting out of sync 
with the server. Fixed by using the button to "delete all 
headers and message bodies" on the local file. But if your 
missing emails are also missing on the server, then this is 
irrelevant.

- My email is retrieved using fetchmail and delivered to my 
mailserver using exim. When moving the whole operation to a 
new server, there was a glitch when some deliveries were 
accidentally made to the old server which was still running. 
  The emails were not lost but they had to be retrieved from 
the old server. As I see that you changed servers 2 years 
ago, is it possible that you have a similar issue?

- Spam filtering and other automated sorting: my Popfile 
system occasionally puts emails into unexpected places. When 
in doubt, I check the Popfile logs. But this is generally an 
issue for current emails. Are your users running any kind of 
sorting or filtering tools?

I really can't see any way in which Dovecot could be 
involved in losing emails from the mailserver.

John

-- 
John Allen
Bofferdange, Luxembourg
allen at vo.lu
http://allenlux.dyndns.org