[sebastian_ita]

After some testing and log reading, I came to the conclusion that maybe in my case the problem could be generated by filters. The user who had the problem used a lot of filters and a lot of nested folders (a message could be filtered more than one time, depending on the sender and other criterions), in some cases where more filters could be applied the message remained stuck, and the pop server never received the delete command, causing the never-ending download of the message. I checked the filters, and they seemd to be correct (in particular the option "don't process other filters" - I have the italian version of the UI, don't know if in English it is the correct translation). As of now, after I disabled the filters, for two days I haven't experienced again the error (I had it daily, often more than one time a day).

I'm writing to know if other people who experienced the problem had a similar configuration (lot of filters, or at least some filters which could clash and some nested folders), so -maybe- in that case a bug report could be created (I expect the program to warn me if filters are creating problems, or at least put the message in a folder and stop the filters if they can't work well instead of blocking the message and forcing me to restart the service).

Thanks in advance for the answers!