Why is an address on my suppression list?
MailBlastr auto-adds an address to your account-wide suppression list on a hard bounce, a complaint, or an unsubscribe — and skips it on every later send to protect your reputation.
Your suppression list is the set of addresses MailBlastr will not send to. It's how the platform stops you from repeatedly mailing addresses that are permanently broken or that have asked you to stop — both of which damage your sender reputation and can violate anti-spam law.
How an address gets suppressed
MailBlastr adds an address automatically in three cases:
- Hard bounce — the receiving server reports a *permanent* bounce (the mailbox doesn't exist, the domain is invalid, or the recipient's server permanently rejected the message). Soft/temporary bounces do not suppress, because the problem is expected to clear up.
- Complaint — the recipient marked your message as spam (a feedback-loop complaint). Complaints always suppress.
- Unsubscribe — a recipient opted out via a campaign unsubscribe link or one-click
List-Unsubscribe, or you suppressed them manually.
POST /emails, batches, and campaigns alike. It only affects *your* account; another account's suppressions never touch yours, and yours never touch theirs.What happens on a send
On every send path, MailBlastr checks each recipient against your suppression list before handing the message off for delivery. Suppressed recipients are skipped — the rest of the send proceeds normally. For a single POST /emails, a suppressed recipient is recorded with a suppressed status rather than being mailed. See Email suppressions.
Should you remove an address?
Usually no — suppression is protecting you. But the right action depends on why the address was suppressed:
| Reason | What to do |
|---|---|
| Hard bounce | Leave it. The mailbox is gone; re-sending only produces more bounces and hurts reputation. Fix the source of bad addresses instead. |
| Complaint | Leave it. The recipient explicitly flagged your mail as unwanted — re-mailing risks legal exposure and more complaints. |
| Unsubscribe | Leave it unless the person genuinely re-subscribes through a new, documented opt-in. |
Keeping the list from growing
A growing suppression list is a symptom — usually of a list that wasn't cleanly opted-in or has gone stale. Tighten consent at signup and practice ongoing audience hygiene.