Suppression Lists

Manage suppressed email addresses to protect your sender reputation in Axene Mailer.

A suppression is an email address that is blocked from receiving your emails. Axene Mailer maintains a suppression list per account to prevent you from sending to addresses that would damage your sender reputation.

Why suppressions matter

Sending to addresses that have previously bounced, complained, or unsubscribed hurts your domain's reputation with mailbox providers. A poor reputation means more of your email lands in spam -- even for engaged recipients. The suppression list is your safety net.

Repeatedly sending to suppressed addresses (by removing them without good reason) can result in your sending domain being flagged or suspended.

Automatic suppressions

The following events automatically add an address to your suppression list:

Trigger	Stored reason
Hard bounce	`bounce` - the recipient address does not exist or permanently rejects mail.
Unsubscribe	`unsubscribe` - the recipient used the List-Unsubscribe link in one of your emails.

You do not need to take any action for these. Axene handles them automatically.

What happens when you send to a suppressed address

A send to a suppressed address is rejected with a clear reason, both via the dashboard composer and the API -- it is never silently dropped.

Suppressions happen automatically, and occasionally by mistake: a transient bounce that wasn't really permanent, or a manual add for the wrong address. Rather than requiring a trip here to remove it, one deliberate retry within 24 hours of a rejection is treated as an override and is delivered. Every attempt after that is rejected again -- the override is one-time, and the address goes back to being fully suppressed.

Via the API, retry with POST /v1/emails/:id/retry on the rejected email, or send again with the same recipient. See Sending to a suppressed recipient for the exact request/response shape. Listing suppressions returns blocked_attempts and override_used_at for each address so you can tell whether its override is still available.

Manual suppressions

Via the dashboard

Go to Suppressions in the sidebar.
Click Add Suppression.
Enter the email address and an optional reason.
Click Save.

Bulk import via CSV

Go to Suppressions.
Click Import CSV.
Upload a CSV file with one email address per line (no header required). Lines without an @ are skipped, and addresses already on the list are left as-is.

CSV import requires the Starter plan or above.

Via the API

The suppressions API is served under /v1/suppressions. The address field is named email_address, and reason is optional - it defaults to manual when omitted.

Add a suppression:

curl -X POST https://mail.axene.io/v1/suppressions \
  -H "Authorization: Bearer axm_k_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "email_address": "[email protected]",
    "reason": "manual"
  }'

Adding an address that is already suppressed returns 409 Conflict.

List suppressions:

curl "https://mail.axene.io/v1/suppressions?page=0&limit=50" \
  -H "Authorization: Bearer axm_k_YOUR_API_KEY"

The list is paginated. page is zero-based, limit accepts 1-200 (default 50). An optional search parameter filters by a substring of the address.

Response:

{
  "items": [
    {
      "id": "b1f7c0a2-3d4e-4f5a-9b6c-7d8e9f0a1b2c",
      "email_address": "[email protected]",
      "reason": "bounce",
      "created_at": "2026-04-01T08:30:00Z",
      "blocked_attempts": 0,
      "last_blocked_at": null,
      "override_used_at": null
    },
    {
      "id": "c2e8d1b3-4e5f-5a6b-0c7d-8e9f0a1b2c3d",
      "email_address": "[email protected]",
      "reason": "unsubscribe",
      "created_at": "2026-04-03T14:12:00Z",
      "blocked_attempts": 0,
      "last_blocked_at": null,
      "override_used_at": null
    }
  ],
  "total": 2,
  "page": 0,
  "limit": 50
}

blocked_attempts, last_blocked_at, and override_used_at track the one-time retry override -- see above.

Remove a suppression:

curl -X DELETE https://mail.axene.io/v1/suppressions/b1f7c0a2-3d4e-4f5a-9b6c-7d8e9f0a1b2c \
  -H "Authorization: Bearer axm_k_YOUR_API_KEY"

When to remove a suppression

Only remove a suppression if you are certain that:

The email address is valid and currently accepting mail.
The recipient has explicitly asked to receive your emails again.
The original issue (bounce, complaint) has been resolved.

If an address was suppressed due to a spam complaint, removing it and sending again without the recipient's clear consent may violate anti-spam regulations (e.g. Kenya's Data Protection Act, GDPR, CAN-SPAM).

Before removing a suppression for a previously bounced address, ask the recipient to confirm their address is working by having them email you first.

Suppression Lists

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