Just a question about how Thunderbird learns to identify junk mail. I tried to ask this in their support, but they require a login through Facebook, Google, etc. and I won't log into anything through any of those except Disqus, which isn't an option.

Does Thunderbird learn on a global level (program-wide), or does it learn separately for each email address? I receive a fair amount of email that's legitimate at one address and not at another. For example, if I have a business relationship with a company then they're within their rights to send me an email at the address I've registered with them but if it comes to any other it's clearly spam. That doesn't mean I necessarily want the message at the correct address, either, but at least it's sent there legitimately.

Mostly, I'm just curious. It might affect how I mark or don't mark some messages.