We've bought our own /24 block of IPv4 addresses. 256 of them, owned by us rather than rented from a hosting provider, and our outbound mail is moving onto them.
Mail servers decide where to put your email partly on the strength of the address it came from, and that address carries a history. Renting means inheriting whatever the last tenant did with it and living with whatever the neighbours are doing now. Change hosts and you start again from nothing. On our own block the only mail those addresses have ever sent is ours, and if we move providers the reputation comes with us.
The other half of it is abuse reports. A spam complaint about forwarded mail used to go to whoever owned the IP, and reached us later and second hand, sometimes only through third-party reporting networks. We're the registered owner now, so the reports come to us directly. That's what our abuse detection runs on, and better reports mean we shut down spammers and abusers faster.
IPv4 ran out years ago, so there's nothing to apply for. You buy a block off someone who already has one, at whatever the market says it's worth, and a /24 is the smallest piece the routing tables will carry. It's a lot of money for something no customer will ever see, which is roughly the point. Forwarding is only worth anything if the mail arrives.
Nothing to do on your side.
Thanks,
Matthew Tse
Owner and CEO @ ImprovMX
