When a recipient hard-bounces or marks your mail as spam, that address is added to your organization's block list automatically and refused at send time.

curl https://api.carlyemail.com/v0/lists/send/block \
  -H "Authorization: Bearer $CARLYEMAIL_API_KEY"

Each entry carries the reason and the event that caused it.

Automatic entries are read-only

You can see them; you cannot delete them. That is deliberate, and it is not us being precious about it: sending providers suspend an account at roughly a 5% bounce rate or a 0.1% complaint rate. Continuing to mail an address that already complained is the fastest route to losing the ability to send at all — for you and, on a shared domain, for everyone else.

A soft bounce — a full mailbox, a temporary server problem — does not suppress. Those recover, and suppressing on them loses real mail.

Your own entries

You can add and remove your own blocks freely:

curl -X POST https://api.carlyemail.com/v0/lists/send/block \
  -H "Authorization: Bearer $CARLYEMAIL_API_KEY" \
  -H 'content-type: application/json' \
  -d '{"entry": "noreply@example.org", "reason": "never reply to this"}'

Watching your rates

GET /v0/metrics/events gives sends, deliveries, bounces and complaints over time, per organization and per pod — so you can tell which agent is generating bounces, not just that something is.