Unsubscribe links

How unsubscribe is handled depends on whether you are sending a transactional email or a campaign.

Transactional emails (sender-driven)

For POST /emails, MailBlastr does not add an unsubscribe link or List-Unsubscribe header. Transactional sends — receipts, password resets, confirmations — are sender-driven: if a message needs an unsubscribe mechanism, you add it to your own HTML. This keeps MailBlastr from injecting footers into messages where they don't belong.

If you manage your own list and want a native one-click control on transactional mail, you can set the headers yourself via the `headers` object — a List-Unsubscribe header pointing at your unsubscribe URL, plus List-Unsubscribe-Post: List-Unsubscribe=One-Click for RFC 8058 one-click support.

"headers": {
  "List-Unsubscribe": "<https://example.com/unsubscribe>",
  "List-Unsubscribe-Post": "List-Unsubscribe=One-Click"
}

When honoring a one-click request, your endpoint should accept a POST from that URL and return a blank 200 OK or 202 Accepted (and serve the normal unsubscribe page on GET). Ensure the recipient stops receiving email within 48 hours. Mailbox providers such as Gmail and Yahoo require RFC 8058 compliance for bulk senders (more than 5,000 messages per day to their domains).

Campaigns (automatic)

For campaigns (marketing email to an audience), MailBlastr injects unsubscribe handling automatically for every recipient:

• A per-contact unsubscribe link is appended to the message footer. Each recipient gets a unique link, so one click opts that individual out.
• An RFC 8058 `List-Unsubscribe` header (with List-Unsubscribe-Post) is emitted so mailbox providers can render a native one-click unsubscribe control.

When a contact unsubscribes through either path, they are added to your suppression list and skipped on subsequent sends. The unsubscribe link is appended after any click-tracking rewrite, so the opt-out link is never wrapped by the click tracker.