BuildYourMailer

Documentation

Overview

BuildYourMailer installs and manages your own Postal mail server on a server you control. You run one command; the installer sets up everything needed to send mail reliably — the mail server, a database, automatic HTTPS, and DKIM signing — then gives you a menu for health checks, DNS records and advanced settings.

Before you start

  • A fresh Debian 12 or 13 server (a VPS is fine), with root access.
  • A domain name you control, to send mail from and point at the server.
  • Outbound port 25 open (many providers block it by default — ask support to open it), and inbound 80/443 for HTTPS.
  • Access to your domain's DNS and the ability to set a PTR (reverse DNS) record at your provider.
  • Your license key (see below).

Get your license

Choose a plan on the pricing page and complete checkout. We email your license key (format BYM-XXXX-XXXX-XXXX-XXXX) and a link to the installer. Keep the key — you'll enter it during installation.

Install your server

Log in to your Debian server as root, download the installer and run it:

curl -fsSL https://license.buildyourmailer.com/install.sh -o install.sh && chmod +x install.sh && sudo ./install.sh

The installer asks for your license key the first time, validates it, and then walks you through setup (hostname, passwords and a few choices).

Keep the install.sh file — re-run it any time to open the menu (health check, DNS records, advanced config) and it won't ask for the key again. Every run still checks your license online, so keep the server connected to the internet.

What you get

  • Postal — the mail server — with its database and background workers.
  • Automatic HTTPS for the Postal web interface (TLS certificates issued for you).
  • DKIM signing and the SPF/DMARC records you need for good deliverability.
  • A management menu for day-to-day operations.

Publish your DNS records

For mail to be accepted by providers like Gmail, publish the records the installer shows on your sending domain:

  • SPF, DKIM and DMARC TXT records (exact values are printed by the installer and the DNS records tool in the menu).
  • A PTR / reverse-DNS record for the server's IP, set at your VPS provider.
DNS changes take time to propagate (minutes to a few hours). If early test emails are rejected, wait for propagation and try again.

Re-run the installer you downloaded (from the same folder) to open the menu:

sudo ./install.sh

From there you can:

  • Run a system health check (containers, database, TLS, mail).
  • Open the DNS records manager to view, verify and export your records.
  • Adjust advanced configuration and re-apply settings.

Move to another server

Movable plans let you re-home your license yourself. On the Manage your license page, enter your key and email, release the current install, then run the installer on the new server to activate it there.

Troubleshooting

MessageWhat to do
License key not recognizedCheck for typos; copy it exactly from your email.
License has expiredRenew from the pricing page to continue.
Already in use on another serverRelease it on the Manage license page, then install on the new server.
Cannot reach the license serverCheck the server's internet connection and DNS.
Emails rejected by Gmail/OutlookConfirm SPF/DKIM/DMARC and PTR are published, then wait for DNS to propagate.
Nothing sends at allYour provider may block outbound port 25 — ask them to open it.

Support

Need a hand? Contact us and we'll be glad to help.