I deleted the mail server from my VPS and got 1.2 GB of RAM back

Description and use

Migrating the mail server from the VPS to smtpfa.st reduced memory usage by 1.2 GB, improved delivery visibility, and enabled a newsletter system.

Problem

The VPS hosted a self‑managed mail server that consumed 1.14 GiB of RAM, provided no visibility into email delivery, and risked IP blocklisting when sending newsletters.

Outcome

Migrating from a self‑hosted mail server to smtpfa.st reduced RAM usage by 1.2 GB, eliminated ClamAV updates, provided real‑time email delivery visibility, and enabled a newsletter system with proper opt‑in handling.

Workflow

• 1. Add smtpfa.st SMTP settings to Django
• 2. Add DNS records in Cloudflare and verify
• 3. Create TransactionalEmailBackend to set X‑SMTPfast‑Category and tracking headers
• 4. Sync user email preferences nightly to smtpfa.st contacts
• 5. Build email templates with React Email, upload as hosted templates
• 6. Create broadcasts via REST API, schedule per time zone
• 7. Handle webhooks for bounces, complaints, unsubscribes with HMAC verification
• 8. Clean old email list and set bounce suppression rule
• 9. Report issues to smtpfa.st and track fixes
• 10. Backup mailboxes, stop/delete containers, close ports, update SPF and MX
• 11. Verify RAM usage drop and monitor email delivery

Evidence

docker stats showed the mailserver using 1.14 GiB

Source

Used RAM went from 5,537 MB to 4,322 MB

Source

smtpfa.st has an SMTP relay so for Django it's only settings

Source