[afidrya]

For example which ones? For past few years I'm using Mail-in-a-Box hosted on soyoustart and can't remember any problems when sending mail to big providers. I only had to check that IP is not in spam lists initially and asked to remove it from one of them.

[cat199]

running email for 15+ years here, going with ditto.

many ppl get el-cheapo vps on a low-tier network, setup some new domain on a dirty IP without proper DNS records (PTR, MX, yadda), and then parrot this

emails not the easiest thing, but it's not impossible either