Re: Nice to See an Article About This
I agree a very welcome article. Been doing this myself with a FreeBSD/Exim/Dovecot setup since before spam was really a problem (and I've since added SA-Exim to the mix for spamassassin integration). Talking of spam, I find that the DNS blocklists reject a lot of this, and it is also particularly nice that this technique rejects the message before delivery is accepted - meaning that you don't generate backscatter spam bounce messages for rejected traffic.
I would like to see some discussion about use of cloud though. My server lives at home, has a static IP and listens to the Internet on port 25. However, I also use an AWS-based server as backup MX (and also primary DNS) because there are occasions that I turn my home machine off for a while. My own issue though is reading email while away. I don't make my IMAP server available via the Internet, so if I am on the move, I generally have to VPN in to my network to read email (although I do also have Gmail for when I am mobile). I'm still not decided on whether to stick with this, open up a port for my local Dovecot to the Internet, or move the whole shebang to an AWS hosted image. It's an area where I'm always interested in what other people are doing and how well it works out for them.