I never had that problem, unless you mean things like the occasional Facebook or Twitter notification ending up in spam, but I didn't care about those. Also, G

I never had that problem, unless you mean things like the occasional Facebook or Twitter notification ending up in spam, but I didn't care about those. Also, Gmail definitely has a problem with false positives. At the small agency where I worked a few years ago, a lot of our internal company emails were ending up in spam folders. It got so bad that I had to go around adding our company email domain to the spam exclusion filters just to make sure that my co-workers were receiving my emails.