Suppression list
The suppression list holds the addresses your sends set aside: hard bounces, unsubscribes and spam complaints, and what each one blocks.
The suppression list is the registry of addresses your sends set aside: no more campaigns for someone who unsubscribed, nothing at all for a dead address or a complaint. Manage it under Account → Suppression list.
Why it exists
Sending another newsletter to someone who has unsubscribed is both:
- illegal — the GDPR and the ePrivacy Directive require you to honor withdrawal of consent;
- damaging to your deliverability — the re-contacted person hits "mark as spam", and every complaint degrades your domain's reputation with Gmail, Outlook and others.
The suppression list makes that mistake impossible: it is a mechanical safety net, not a good intention.
How an address gets on it
Each entry carries its reason:
| Reason | Source |
|---|---|
| Unsubscription | The person unsubscribed. |
| Bounce | The address does not exist or rejects emails (automatic). |
| Complaint | The person marked an email as spam (automatic). |
| Manual | You added it yourself. |
What the refusal behind a bounce means, and whether it is temporary or permanent: SMTP error codes.
When you add an address manually, the corresponding subscriber immediately moves to unsubscribed status: they disappear from all targeting at that instant.
What each reason blocks
| Send | Unsubscription | Bounce, complaint, manual |
|---|---|---|
| Campaign, automation | Set aside | Set aside |
API with unsubscribe_url | Refused | Refused |
API without unsubscribe_url | Goes out | Refused |
An API email that carries unsubscribe_url is a newsletter or prospecting: it is treated like a campaign. Without that field, the email is individual — a reply, an invoice, an appointment. Leaving your newsletter is not refusing the answer to one's own request: those emails still reach someone who unsubscribed. A dead address or a complaint applies to everything you send, and so does the platform blocklist.
An unsubscription never replaces another reason: an address that bounced and then unsubscribed stays refused everywhere.
What the list guarantees
- At import: an address on the suppression list found in your CSV is imported as unsubscribed, never active. Details here.
- On removal: removing an address from the list does not reactivate the subscriber — they remain unsubscribed. Only an explicit new consent from the person would justify re-subscribing them.
- Platform-level blocklist: in addition to your list, Mailcheer maintains a global suppression list that applies across all workspaces.
The one reflex to remember
Switching from another email tool? Export its unsubscribes and bounces too, and add them to your suppression list before importing your contacts. Your reputation will thank you.