Personally I disabled Gmail’s spam filter long time ago[0]. (False positives plus I have some weak morbid curiosity as what comes in spam.) Not getting too much junk so far.

Recently I started to give a different email to each service so that I can see if any get compromised, but so far I don’t think I’ve noticed anything like that.

[0] I borrowed someone’s workaround where you create a filter that excludes emails matching a specific random UUID, which no email would match, with action “never send to spam”. Perhaps there’s now a more straightforward option.

There's no way to disable spam filtering in Gmail because most of the filtering happens long before user filters are checked.

If it weren't true, or spam folders would contain thousands of messages.

My spam folder receives no more than a dozen of messages per month and I know that there're tens of thousands attempts to send me a spam.

I agree that there may be earlier filtering stages, though in my experience even if you send unauthenticated messages from not-really-configured postfix on Ubuntu they would still be viewable in recipient’s spam, or at least that was the case a few years back.

I’m pretty sure recruiters’ emails peterwwillis mentioned would not be as bad as to be eliminated before spam folder.

They used to have smart labels in the gmail labs config section, but dropped it. It appeared to be a Bayesian classifier. You couldn't add your own labels, but it did work well. No idea why they dropped it.

You could use popfile, it supports moving mail to named folders, which isn't the same as just applying a label, but works. http://getpopfile.org

There is a "filter similar message" option available (it is hidden with the answer /transfer / print / etc options).