Send email from Django.

Before you start

You need a verified sending domain (see Domains) and an API key (under API keys in the dashboard; it is shown once). For SMTP the key is the password, and a sending-only key is enough. Keep the key in an environment variable on your server, never in code that runs in a browser or an app.

1import os
2​
3EMAIL_HOST = "smtp.mailtruss.com"
4EMAIL_PORT = 587
5EMAIL_HOST_USER = "mailtruss"
6EMAIL_HOST_PASSWORD = os.environ["MAILTRUSS_API_KEY"]
7EMAIL_USE_TLS = True
8DEFAULT_FROM_EMAIL = "hello@yourdomain.com"

Try it without sending real mail

From python manage.py shell, send a message to the test address. It needs no verified domain and reaches no real mailbox.

1from django.core.mail import send_mail
2send_mail("Test", "Hello from Django", "hello@yourdomain.com", ["delivered@mailtruss.test"])

See what happened

Open the message under Emails in the dashboard: it shows the recorded timeline, what each event proves, and a diagnosis if something went wrong. Mail sent over SMTP appears there like any other message. To be told as it happens, add a webhook.

If it fails

The relay answers with a reply code:

• 535: the API key is wrong or revoked. Fix the password.
• 550: refused for good (unverified domain, suppressed recipient, invalid message). Do not retry; the reply says why.
• 552: too large, or the monthly limit is reached.
• 451 or 452: temporary (rate limit, daily limit, or a brief problem on our side). Retry later; mail servers do this automatically.

Problems that happen after a message is accepted (bounces, complaints) are explained under delivery errors.

Other guides

• Next.js
• React Email
• Express webhooks
• Supabase Auth
• Laravel
• Rails
• Nodemailer