Self-Host Your Newsletter: The arithmetic of Postal, Listmonk, SES, and when it's worth it

The spreadsheet is honest. The operations bill is the one nobody puts in the blog post. Amazon parks every new SES account in a sandbox that caps you at 200 messages every 24 hours and only to addresses you have already verified. Getting out of that, warming a fresh IP over four weeks, configuring SPF, DKIM, DMARC, and BIMI, signing up for feedback loops with Yahoo and Microsoft, and keeping your Gmail spam rate under 0.30 percent before your first real batch goes out: that is roughly an eight-week ramp, not a Sunday afternoon.

I wrote this because I believed the Sunday-afternoon version and paid for it with a bruised domain reputation. The book is the cost-honest version I wish I had read first. It walks the spreadsheet across Mailchimp, Beehiiv, Substack with its 10 percent cut, and the self-hosted stack, then through Listmonk, Keila, Sendy, and Postal so you can tell the maintained tools from the abandoned weekend projects. There is an SES production-access letter that gets approved on the first try, a bounce-handling daemon that keeps your account from auto-suspending, and an honest count of the two to four hours a month this actually costs once it stabilizes.

If you run a list somewhere between eight and twenty-five thousand subscribers and you keep staring at the invoice, this is the self-hosted newsletter book about Postal, Listmonk, Keila, Amazon SES, IP warm-up, and the sender reputation work that decides whether any of it lands. Written from running small businesses in Indonesia, but the deliverability math and the operations checklist read the same in any emerging market or one-person shop.