Why It Matters
Ignoring your suppression list is one of the fastest ways to destroy your sender reputation and potentially face legal consequences. CAN-SPAM requires that you honor unsubscribe requests within 10 business days. Sending to someone who's opted out can result in fines of up to $51,744 per email. Beyond the legal risk, re-mailing suppressed contacts leads to complaints that directly damage your deliverability.
How It Works
Your suppression list should include several categories of addresses:
- Unsubscribes — Anyone who clicked your unsubscribe link or replied asking to be removed.
- Complaint reporters — People who hit the "Report Spam" button in their email client.
- Hard bounces — Addresses that returned permanent delivery failures.
- Manual removals — People who contacted you directly asking to stop receiving emails.
When you switch ESPs or upload a new list, your suppression list must be applied first. This is where many senders mess up — they migrate to a new platform and accidentally re-mail everyone they'd previously suppressed.
Quick Tips
- Export your suppression list before switching email platforms and import it into the new one before sending anything.
- Never delete suppression records — archive them if you must, but keep the data so you never accidentally re-add someone.
- Check that your suppression list is being applied at the campaign level, not just the list level. Some platforms handle this differently.