Thunderbird not syncing junk folder / not showing unread junk emails

Question

Thunderbird fails to sync junk folder unless user clicks on junk folder specifically. How can user sync junk folder automatically (since otherwise there is a chance FPs might go unnoticed)?.

Thunderbird is latest version 52.2.1 32 bit on Windows 10, all folders are subscribed, tried pressing "Get All new messages" several times, restarted Thunderbird, tried disabling/enabling adaptive junk filter option. Server used is Dovecot IMAP with subscribe turned on. Issue does not happen in other clients where upon receiving junk message the junk folder shows unread message flag.

Answer 1

It appears Thunderbird does not automatically sync junk or trash folders by default (tested latest stable and beta versions on Windows 10). The solution was to include junk folder in message synchronization settings (offline use settings).

Tools > Account settings > Synchronization and storage > Advanced > Select junk folder.