I am running Thunderbird 102.6.1 in a Windows 10 Pro environment. I am also using the QuickFolders and Provider for CalDAV & CardDAV extensions. My Thunderbird is configured to work with four gmail.com accounts, all as POP rather than IMAP. Whenever I receive a new message I get the traditional "ding," and two minutes later I get the "ding" a second time. The messages, however, do not download more than one time each. The message count in the Windows 10 task bar shows double the number of messages that I actually have in my Inbox. This problem began happening sometime in mid-2022 and I cannot figure out what I did to cause it, or how to remedy it. Anyone have a solution to this problem?