Why email59 Refuses Marketing Email: Transactional Only, No Promotions

Most email delivery providers try to be everything at once: transactional receipts and giant marketing blasts on the same shared networks. When spammers and marketers burn domain reputations, everyone's delivery suffers. email59 is one of the first email services that strictly refuses marketing email.

We only deliver genuine transactional email: purchase receipts, password resets, sign-in codes, order tracking, and account notices. Here is how our filters keep marketing out.

Marketing routes are completely closed

If you try to send a newsletter, a promotional campaign, or a marketing blast, the API refuses the request before anything leaves the server:

• Bulk campaigns are closed. Any request to POST /v1/campaigns returns HTTP 403 marketing_not_allowed.
• Marketing category is refused. Setting category: "marketing" on POST /v1/send returns 403 marketing_not_allowed.
• Opt-in list creation is closed. Calling POST /v1/optin returns 403 marketing_not_allowed.

Here is the exact response from the server:

HTTP/1.1 403 Forbidden
Content-Type: application/json

{
  "detail": {
    "error": "marketing_not_allowed",
    "message": "email59 does not carry marketing email: campaigns, marketing sends and list opt-ins are closed. Send transactional email (receipts, codes, alerts, notices) with POST /v1/send."
  }
}

How transactional sends are scanned

Some senders try to slip marketing pitches into transactional endpoints like POST /v1/send. Our send policy scans the subject, text, HTML, headers, and button text before delivery:

• Strong marketing phrases trigger an immediate refusal. Any single match for phrases like buy now, shop now, discount code, use code, flash sale, limited-time offer, black friday, or % off halts the send.
• Weak phrases are caught in pairs. Everyday words like free shipping, hurry, deals, new arrivals, or promotion won't trigger a refusal on their own (so receipts with standard shipping notes pass), but two or more together trigger a refusal.
• Your allowance is never deducted. When a send is refused, zero email allowance is spent. You can fix the wording and try again without losing credits.

A worked example request and 422 refusal

Here is what happens when a test call tries to send a promotional offer through POST /v1/send against https://email59.com:

curl -s -X POST https://email59.com/v1/send \
  -H "Authorization: Bearer e59_test_samplekey123" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "store",
    "to": "customer@example.com",
    "subject": "Weekend Special Offer",
    "text": "Check out our new arrivals and shop now to save up to 20% off your order!"
  }'

The API rejects the email immediately with HTTP 422:

HTTP/1.1 422 Unprocessable Entity
Content-Type: application/json

{
  "detail": {
    "error": "content_not_allowed",
    "reasons": [
      "marketing"
    ],
    "words": 0,
    "passages": 0,
    "marketing": [
      "20% off",
      "shop now",
      "special offer",
      "check out our",
      "new arrivals"
    ],
    "message": "email59 carries non-marketing email only: no promotions, newsletters or offers. Email from a kid-safe address must also be kid-safe: no bad language or sexual content, English text only. Change the email and send it again."
  }
}

Why this matters for your app

By completely refusing promotional mail, email59 keeps delivery channels clean and fast:

• Your critical receipts and login codes arrive in seconds. Transactional queues never get backlogged behind millions of bulk marketing newsletters.
• Inbox providers trust our senders. Major email providers recognize that email59 does not pump out marketing spam, helping your messages land in the Primary inbox.
• Recipients know emails are important. Users open email59 messages knowing they are receiving real account updates, not another sales pitch.

Ready to send clean transactional email?

Sign up with an email code in two API calls and start sending transactional notifications in minutes.

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