> Either that, or you need your own IPs.
Or just use IPv6, which will probably fix this.
Re:What does /etc/mailname do?
by oarsinsync on Thursday February 13, 2020 @02:40AM
(#22316021)
This'll stop being true at cheap VPS providers as soon as spammers cotton on, and then VPS providers ranges will be blocked in /48s (even if you only get a /128 or /64 from your VPS provider) because it's not worth the hassle of doing anything smaller.
Re:What does /etc/mailname do?
by scintill76 on Wednesday February 12, 2020 @04:59PM
(#22313258)
Why is this considered a useful signal by Gmail? Isn't it cheaper for a spammer to get throwaway IPv6 addresses?
Re:What does /etc/mailname do?
by inopinatus on Wednesday February 12, 2020 @06:04PM
(#22313757)
Most spammers aren’t competent to provision an IPV6 service correctly, especially one with matched PTR and SPF(TXT) records, and using throwaway v6 addresses makes SPF much harder. It’s also easy to spot, at which point you can tag the sender domain with a bad reputation.
It’s no surprise that Gmail et al are more interested in sender domain reputation, and also the graph of related domains, than they were a few years ago.
This is the most likely situation. If a VPS provider is sufficiently cheap, it will attract the wrong people, who will then get the entire VPS provider's IP blocks blacklisted.
It's a shame, but it's the reality. There are lots of discussions around this subject on various mailing lists, where people from the likes of Gmail have chimed in stating as much.
I would reckon it takes as little as 10% of the addresses in a /24 (so ~25 IPs) to get that entire netblock blacklisted.
If you want a higher probability of clean IPs, you need to be using a provider that is sufficiently expensive to not attract spammers.
Either that, or you need your own IPs.