Oh, I do think that Google is absolutely more aggressive than they probably should be on filtering... On the flip side, there's very little other choice. The VAST majority of email comes from a handful of hosts/providers and everything else has a much higher noise to signal ratio and gets much more scrutinized period.

Also, if you aren't sending a lot of mail, consider relaying outbound through mailgun or a similar service (I used to use sendgrid myself). Nearly zero issues when doing this on the lowest level paid account. That said, inbound spam was so painful to deal with I just gave it all up.