I desperately need help!!! I've been using Thunderbird for last fourteen years and now I can't solve a problem that makes TB useless. 1. I've noticed that within last 6-8 months to move to another folder or delete a message with a larger attachment takes longer and longer (let's say above 1Mb) 2. About 2 months ago for the first time I got message "Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox." This happened when there was an email with 2.5 Mb attachment. 3. Now emails with even smaller attachments give me this message blocking following emails to download. 4. Once email with attachment is deleted on web browser e.g. gmail other/newer emails are downloaded. In the past there was not a problem with way bigger attachments. I went through almost all topics posted in this support as well as many others. For last two months I did almost everything that was advised e.g. from those links https://kb.mozillazine.org/Keep_it_working_-_Thunderbird http://kb.mozillazine.org/Unable_to_write_the_email_to_the_mailbox Yesterday I even installed clean version of Thunderbird and when started downloading messages again same story happened. I'm desperate since I can't work this way. This issue is related to POP accounts, IMAPs work ok. I'd highly appreciate if somebody could help me. Kristof