Since upgrading to 4.14.1 and now 4.14.2 from the Kubuntu 14.04 backports PPA I experience a very annoying issue with kmail/kontact each time I wake the computer from sleep.

New mail appears to be fetched normally, but Kontact remains stuck at "Retrieving folder contents" when I select messages or change folders or even (imap) accounts. Switching it off/online does not unblock the situation, I need to restart akonadi.

After the 1st `akonadictl restart`, the situation appears to be unblocked, but the mail filter agent remains at 0% indefinitely according to both kontact's progress widget and akonadiconsole. A second akonadictl restart is required within a short laps of time in order to return things to normal. Then one can see the mail filter resource do some actual work at some point of the synchronisation process.

Given that this is on a netbook, we are by now long minutes from the moment I woke the computer from sleep.

kontact/kmail usually get in the same "Retrieving folder contents" catatonic state after having been kept offline for a while. Under 4.13.3 this was my most reliable way of preventing the "gmail too many simultaneous connections" bug by having only 1 kontact process online on 1 computer at a time.

Reproducible: Always

Steps to Reproduce:
1. Wake computer from sleep in the morning
2. Ensure it connects to the correct WLAN and enter the wallet password in the dialog posted at kontact/akonadi's request
3. Wait for sync to complete, try to read new (or even old email)


Actual Results:  
4. when it's clear kontact won't display anything else but "Retrieving folder contents",
5. do akonadictl restart
6. admire the dance in the expanded kontact progress widget and notice how the mail filter agent appears there
7. remark that said filter agent is going to remain stuck at 0% again (long) after everything else settles down (and you can actually read email)
8. do another akonadictl restart
9. as in 6, but this time the filter agent actually does things and completes its job

Expected Results:  
to be able to start handling email normally after a wake from sleep or lengthy period of having kept kontact/kmail offline.

I'm attaching a log of output obtained after entering akonadictl restart in a terminal, with debug output activated for the mail filter agent. It starts with the last output from the server processes being stopped (which look suspicious) and then shows the trace of new processes being started. It includes the output from the 2nd `akonadictl restart` required to return to normal functioning, and from what I can see it is only after that restart that output from the mail filter agent appears in the log.

It turns out that mailfilter has the same "no progress" issue when akonadi is restarted after functioning normally for a while.

A very similar issue plagues my "kdepim user experience" under OS X with kdepim 4.13.3 and akonadi 1.13.0 and (of course) a mostly identical configuration (accounts, kontact settings).

Possibly related observation: regularly email deleted from my main gmail imap account is moved not to the configured trash (on the gmail server) but to my local mail trash.