Tricky thing about Google is quite a lot of my contacts are on Gmail or some domain hosted by Gmail so blocking Google's ASN is a no go for me. I'm now with Fas

Tricky thing about Google is quite a lot of my contacts are on Gmail or some domain hosted by Gmail so blocking Google's ASN is a no go for me. I'm now with Fastmail -- they use Spamassassin (plus I suspect their own custom rules) which uses a range of different metrics to determine whether an email is spam. That is is far more effective than straight up blocking ASNs and the like.