A forwarder to gmail is successful, but mail is missing when downloading from POP

[spaceman]

This is a problem that I thought I could resolve myself. But so far I've failed, and appear to be no closer to the solution. Any help would be massively appreciated.

My wife has a POP email address on one of our cPanel servers. She downloads mail from that pop account using Thunderbird. A few months ago she became aware that not all legitimate email sent to her was apperting to get through (i.e. appearing in her inobx). The vast majority yes, but not all.

So here's what I've done:
1. Turned off ALL filtering in thunderbird - including both anti-spam and manually created filters. I've checked and checked and checked again that all email successfully downloaded from the server should be going directly into her inbox and nowhere else.
2. In cPanel setup a forwarder so that all email received by her POP account is automatically forwarded to a gmal account.

And here's what we've proved: every so often, email IS appearing in gmail that is absolutely not appearing in her Thunderbox inbox.

* I've tried deleting and re-creating the POP account. Still this problem occurs.
* I've checked the log files (exim_mainlog, rejectlog and paniclog). As far as they are concerned, the missing messages *were* successfully received by the server (see below) and delivered to the POP account. There are no signs of any errors or filtering going on at the server. So why aren't then in my wife's inbox?

2007-02-06 21:43:06 1HEPf6-0000Rv-QY => emma F= R=virtual_user T=virtual_userdelivery S=1468
2007-02-06 21:43:06 1HEPf6-0000Rv-QY Completed

* I sent a test message myself late one evening. Next morning the message was not in her inbox in Thunderbird. I resent the exactly the same message - it arrived almost instantly in Thunderbird, Why did it not arrive first time in her Tbird inbox, but it did the second? Server logs confirm successful receipt, no rejections, of both messages, both times.

It's very hard to gauge the frequency of this issue. At a wild guess I'd say perhaps anywhere from 1% to 0.5% of my wife's total non-spam emails are arriving in gmail (thanks to the forwarder) but not into her tbird inbox for no apparent reason.

* I've recently set tbird to leave messages on server for at least 7 days. So I'm hoping that I can identify a message that is in gmail, is not in tbird's inbox, but is still stored on the server in her pop account. And then perhaps I'll be able to work out why it refuses to be downloaded.

Any additional help or suggestions or insights anyone?? I will get to the bottom off this, one day. In the unlikely event that I don't, then my wife is considering abandoning email client software completely in favour of web-based email only.

Thx!

[spaceman]

anyone? :-)

[nisse]

Have you checked the actual inbox folder on the server to see whether the message files for the missing emails are in there?

[spaceman]

Good question :-)

The answer is, yes I have. The result: I cannot see the missing email in the inbox on the server. I can see messages either side (with respect to date) of where the missing message would be.

Until yesterday I set Thunderbird to leave messages on the server for up to 7 days, but even by doing this the server appears only to keep them for 24 hours or thereabouts.

So yesterday I've set Thunderbird to leave all message on the server, and made sure the account is set to an unlimited storage quota.

So hopefully the trap is now totally set! We're now checking for a message that:

1. Is in the gmail inbox (thanks to the forwarder)
2. Is *not* in the Thunderbird - inbox or anywhere at all (but should be)
3. And if/when the two conditiona are met (again, as we've observed in the past), THEN we'll be in a position to see whether or not the message is visible in the inbox on the server.

Clearly an error is going on here somewhere, and I can't wait to learn where it is. Watch this space. :-)