I am new to Thunderbird. W7Pro, Have a problem with synchronization with web based IMAP email account. Set up the account and it went out and found all the folders including sub folders, but only downloaded (meaning synchronized) to about 50% of the folders. In some cases, the main folder (which had messages) did not synchronize, but sub folders of a main folder did. Any folder that did synchronize completed. In the settings for synchronization, all boxes are checked. I have done significant troubleshooting research but can't find a solution. Also have Outlook 2013 which does synchronize, but very slow. Wanting to switch. At this point I have not made Thunderbird the default email program. Also, I tried to import the addresses from outlook without 'usable' success.