[Users] Ghost emails / very strange POP behavior

[Michael]

And to clarify, Paul: I was wondering if the mails became invisible *locally* on my PC, somehow. Let's say some weird issue with the file system driver or whatever crazy shit; causing claws to not show them until another mail was added to the thread ?
Because this would be a possibility how those mails 'disappeared' from the server - they simply got downloaded and removed. 
It's way more plausible that they really weren't there anymore, and got 'lost' on the PC somehow.

Is there any weird combination of faults that could lead to such an outcome ? Plus, having them 'restored' later ?

(But my PC did not crash for a long time, if that's your next idea.)