I recently switched over 6 gmail accounts (both personal and business) from gmail to fastmail. I have been suddenly bombarded with a mountain of spam that the goog must have been catching. It doesn't seem like my constant flagging is doing anything. I ended up building a convoluted mess of filters that will probably cause me to misflag something important one day. :-/
Also, I really miss the auto categorization into primary, promotions, social and updates. This is a killer feature!
I'm happy to be rid of the goog's convoluted management console, but wondering why fastmail's spam filters aren't up to snuff...