Configure Ghost transactional email over SMTP

Self-hosted Ghost sends staff invitations, password resets, member signups and member login links through the `mail` block in `config.production.json`. Newsletters are a separate path: Ghost delivers them only through Mailgun's bulk API and can't use SMTP, so this setup covers everything except newsletter sends.

1. 1

   Create a send-only key

   In Unitpost, open Settings → SMTP and create a send-only key. Ghost sends from mail.from, so use an address on a verified domain.

2. 2

   Add the SMTP transport

   In config.production.json in your Ghost install directory, add a mail block. Ghost hands options to Nodemailer, so secure: false on port 587 upgrades with STARTTLS, and secure: true belongs with 465.

   JSON

   "mail": {
     "transport": "SMTP",
     "from": "Your Site <noreply@yourdomain.com>",
     "options": {
       "host": "smtp.unitpost.com",
       "port": 587,
       "secure": false,
       "auth": {
         "user": "unitpost",
         "pass": "pk_live_..."
       }
     }
   }

   Running Ghost in Docker? Every config key has an environment variable form with double underscores, such as mail__transport=SMTP, mail__options__host=smtp.unitpost.com and mail__options__auth__pass.

3. 3

   Restart Ghost

   From the install directory, restart with Ghost-CLI so the new config loads. In Docker, recreate the container instead.

   Shell

   ghost restart

4. 4

   Send a test

   Invite a staff user from Ghost Admin, or request a password reset from the /ghost sign-in page. The email shows up in Unitpost Emails.

5. 5

   Newsletters stay on a bulk API

   Ghost's FAQ says newsletter delivery requires a bulk mail API and can't use SMTP, so the transport above never carries newsletters. Ghost doesn't require its built-in newsletter feature, though: you can export members and send newsletters as Unitpost campaigns instead.