Title: Email delivery Description: Configure authentication and notification email for self-hosted instances. Canonical: https://openpo.st/docs/self-hosting/email Source: [https://openpo.st/docs/self-hosting/email](https://openpo.st/docs/self-hosting/email) # Email delivery Self-hosted OpenPost can start without an email service. Add one before you depend on password resets, workspace invitations, email notifications, or required signup verification. Pick one of the transports below and use a sender address on a domain you control. ## SMTP Get the host, port, login, and TLS mode from your mail provider. Add them to the server `.env` file: ```dotenv OPENPOST_EMAIL_PROVIDER=smtp OPENPOST_SMTP_HOST=smtp.example.com OPENPOST_SMTP_PORT=587 OPENPOST_SMTP_USERNAME=mailer OPENPOST_SMTP_PASSWORD=replace-me OPENPOST_EMAIL_FROM="OpenPost " OPENPOST_SMTP_TLS_MODE=starttls ``` Use port 465 with `OPENPOST_SMTP_TLS_MODE=tls` when your provider uses implicit TLS. OpenPost rejects unencrypted SMTP to non-loopback hosts. If the provider requires a different certificate hostname, set `OPENPOST_SMTP_SERVER_NAME` to the name on the certificate. ## Resend Verify a sending domain in [Resend](https://resend.com/docs/dashboard/domains/introduction), then create a key with [Sending access](https://resend.com/docs/dashboard/api-keys/introduction). Set a sender on the verified domain: ```dotenv OPENPOST_EMAIL_PROVIDER=resend OPENPOST_EMAIL_FROM="OpenPost " OPENPOST_RESEND_API_KEY=your-resend-key ``` ## Cloudflare Email Service Onboard your domain in [Cloudflare Email Sending](https://developers.cloudflare.com/email-service/get-started/send-emails/) and create an API token with Email Sending permission. OpenPost uses the Cloudflare REST API, so it needs the account ID and token: ```dotenv OPENPOST_EMAIL_PROVIDER=cloudflare OPENPOST_EMAIL_FROM="OpenPost " OPENPOST_CLOUDFLARE_EMAIL_ACCOUNT_ID=your-account-id OPENPOST_CLOUDFLARE_EMAIL_API_TOKEN=your-api-token ``` ## Verify delivery 1. Run `docker compose up -d` after editing `.env`. 2. Invite a test address to a workspace or request a password reset for an account you control. Check both the inbox and your mail provider's delivery log. 3. Only after delivery works, set `OPENPOST_EMAIL_VERIFICATION_REQUIRED=true` if new password accounts must verify their address, then recreate the container again. If mail does not arrive, check `docker compose logs --tail=100 openpost`, the provider's sender verification, credentials, SMTP TLS mode, and the recipient's spam folder. An accepted send is not proof the message reached the inbox. Delivery callbacks, when configured for a supported provider, use `POST /api/v1/email/delivery/webhook` and `OPENPOST_EMAIL_DELIVERY_WEBHOOK_SECRET`.