Add a suppression

POST/v1/admin/suppressionsAdmin key

After this, live sends to the address fail with 422 recipient_suppressed in every project. Sends with test keys don't check the list.

Adding an address that is already suppressed succeeds and keeps its original entry, with one exception: a complaint reason replaces the stored reason.

Body parameters

addressstringrequired

The email address. Trimmed and lowercased.

reason'manual' | 'hard_bounce' | 'complaint'default: manual

Why the address is suppressed.

Response

Status 201 with the stored suppression and a note reminding you that Cloudflare keeps its own, separate list.

Errors

Status	Code	When
400	`invalid_body`	`address` is missing or not an email address, or `reason` is not one of the three values.

Request

const res = await fetch('https://mailer.example.com/v1/admin/suppressions', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.FLARESEND_ADMIN_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ address: 'grace@example.com' }),
});
const suppression = await res.json();

Response

{
  "address": "grace@example.com",
  "reason": "manual",
  "sourceEmailId": null,
  "createdAt": "2026-09-26T11:00:00.000Z",
  "note": "This is Flaresend's local mirror. Cloudflare keeps its own suppression list; edit that one in the Cloudflare dashboard (Email Service)."
}

Body parametersCopy Anchor Link

ResponseCopy Anchor Link

ErrorsCopy Anchor Link

Body parameters

Response

Errors