OK, so this is something I just noticed, but apparently it's going on from before every of the things described above has happened.
I had one of my Yahoo accounts (that I use to subscribe to different mailing lists) set up with a filter in TB, that automatically forwards emails received from a certain address to somebody's else email address. Basically a filter which forwarded messages. The issue boils down to the fact that for about a couple of months all the automatic forwarding seems to have failed (no new message in the Sent folder of that account in TB, since early August). By trying to manually send a test message today, I constantly got an error message saying: "An error occurred while sending mail. The mail server responded: Error Sending Email. Please check the message and try again." The error console kept popping up tons of lines with the same message, when trying to send: "DebugLog.js : Exception in WriteToFile NS_ERROR_FILE_NOT_FOUND. Error message: Component returned failure code: 0x80520012 (NS_ERROR_FILE_NOT_FOUND) [nsILocalFile.isFile]" I've sent the log files which are created be the WebMail extension when I try to send the test message. Oddly enough, another one of my Yahoo mail accounts seems to be able to send messages, even though at times it fails too. But through this another account (the one with the forwarding filter), I couldn't succeed in sending even a single message even if it contained only a single text line. Any ideas?
