Thunderbird 68.12.1 converted to new Yahoo security by deleting old account and adding new account. Configured for POP3 with ServerSettings/Advanced set to Inbox for Different Account - Local Folders and Include This Server checked. This should be exactly the same as my old configuration. The new configuration does not Check for new messages at Startup (box checked) and does not automatically download them. It will download them when you click Get Messages. It does automatically download message when I set Check For New Messages Every 1 minute. When you start up Thunderbird, it just says Done in lower left corner. After the 1 minute download, it says No Messages To Download. I have Multiple Profiles and the ones I haven't converted are working normally. Any suggestions?