For the last couple of days, transactional emails from my
#rails app have been sent through my own SMTP service.

A dumb idea overall, but it seems to work (most of the time 😅)!

Spamhaus' approach to API is really interesting.

They use DNS as a key-value store. Need to lookup an IP or domain? Just check the TXT record for
<domain>.​dbl.​spamhaus​.org to see if it's listed as a spam domain.

It's super fast and pretty much every email service uses it.

Everyone says running your own SMTP relay is a stupid idea. I wanted to try anyway:

- built a SMTP server in Go*
- set it up to relay emails from Rails
- and forward incoming emails to Rails
- got blacklisted on Spamhaus for testing gmail error responses

👇