Every bounced email is a signal to Gmail and Outlook that something is wrong with your sending practices. Too many bounces and your emails start landing in spam — or stop being delivered entirely.

We just shipped suppression lists on PrimeTimeMail.

What it does

When an email bounces or a recipient marks it as spam, that address is automatically added to your suppression list. Any future send attempts to that address are blocked before the email is ever sent.

Why it matters

Mailbox providers track your bounce rate. Above 2-3% and you're treated as a low-quality sender. The consequences are immediate — spam folder routing, temporary blocks, or permanent blacklisting.

Managing it via API

# List suppressed addresses
curl https://api.primetimemail.com/v1/suppressions \
  -H "X-API-Key: ptm_live_..."

# Add manually
curl -X POST https://api.primetimemail.com/v1/suppressions \
  -H "X-API-Key: ptm_live_..." \
  -d '{"email": "bad@example.com", "reason": "manual"}'

# Remove
curl -X DELETE https://api.primetimemail.com/v1/suppressions/bad@example.com \
  -H "X-API-Key: ptm_live_..."

Free on all plans at primetimemail.com