a few days ago out of the blue, Thunderbird started giving me an error message saying that my password was incorrect. It wasn't, I've logged into the web mail and everything is working perfectly. It's also stopping me deleting messages today that are junk. This has also happened out of the blue. I haven't downloaded any software that could have caused an incompatibility and the firewall was working perfectly. What's up? I've gone over all the settings and they seem fine. Is this a virus?