How bounces, unsubscribes, and complaints work
What happens when an email bounces, someone unsubscribes, or marks you as spam — and why those contacts are protected from future sends.
Updated
Thunk Mail manages the contacts you shouldn't email again. There's nothing for you to clean up by hand, and no list to maintain on the side.
Bounces
A bounce means an email couldn't be delivered.
- Hard bounce. The address is invalid or doesn't exist. We stop sending to it.
- Soft bounce. Something temporary, like a full inbox or a server that's down. We may retry, but an address that keeps soft bouncing gets treated as undeliverable.
Bounced contacts are flagged and left out of future campaigns automatically.
Unsubscribes
Every email carries a one-click unsubscribe link. Anyone who uses it comes out of future sends immediately. That's legally required, and honoring it fast is also what keeps your reputation intact.
Spam complaints
When someone clicks "mark as spam," that's a complaint. Nothing damages deliverability faster, so a contact who complains is suppressed from every future send straight away.
You don't pay for unreachable contacts
Bounced and unsubscribed contacts don't count toward your plan's contact limit. You're never paying to store an address you can't email.
Why this matters
Mailbox providers watch how senders handle bounces and complaints. Gmail and Outlook both do. Suppressing these automatically is a large part of why your next campaign lands in an inbox rather than a spam folder.
Next: Why was my contact blocked? covers what happens when an address is refused before you ever send to it. Deliverability 101 covers the habits that keep these numbers low.