Automatic list hygiene, built in
Most email providers leave bounce handling, complaint tracking, and list cleaning up to you. You have to monitor delivery events, build logic to track failures, update your database, and remember to check before every send. SendKit does all of this automatically. Every bounce, every spam complaint, every unreachable address is tracked and suppressed for you — with zero configuration and zero code. Just send your emails and let SendKit protect your reputation.You don’t need to build any bounce handling logic. SendKit’s suppression list works out of the box for every email you send — via API, campaigns, or automations.
What SendKit handles for you
Hard bounces — suppressed instantly
When an email permanently bounces (mailbox doesn’t exist, domain is invalid, recipient server permanently rejects), SendKit immediately and permanently suppresses that address. You’ll never accidentally send to it again. No webhook handler to build. No database to update. It just works.Soft bounces — smart threshold detection
Soft bounces are temporary failures — a full mailbox, a server temporarily down. SendKit doesn’t suppress on the first soft bounce. Instead, it tracks them intelligently:- 1st or 2nd soft bounce — Address stays active, SendKit keeps trying
- 3rd soft bounce — Address is automatically suppressed
- Successful delivery after a soft bounce — Counter resets to zero
Spam complaints — immediate protection
When a recipient marks your email as spam, SendKit immediately suppresses their address. This is critical — continuing to send to people who complained is the fastest way to destroy your sender reputation and land in spam folders.Automatic enforcement on every send
Every email you send through SendKit — whether it’s a single API call, a batch send, a campaign, or an automation — is automatically checked against your suppression list. Suppressed addresses are blocked before they ever reach the email provider. You don’t need to query the list yourself. SendKit handles it.Manual suppressions
You can also manually suppress addresses through the API or the dashboard. This is useful for:- Honoring unsubscribe requests
- Removing known bad addresses before a campaign
- Proactively blocking addresses you know are invalid
Suppression reasons
Each entry has a reason so you always know why an address was suppressed:| Reason | Description | Added by |
|---|---|---|
bounce | Hard bounce, or 3+ soft bounces | Automatic |
complaint | Recipient marked as spam | Automatic |
manual | Added via API or dashboard | You |
Removing a suppression
You can remove an address from the suppression list through the API or the dashboard.FAQ
Do I need to build any bounce handling logic?
Do I need to build any bounce handling logic?
No. That’s the point. SendKit handles bounces, complaints, and list hygiene automatically. You just send emails.
Is the suppression list shared across my team?
Is the suppression list shared across my team?
Do suppressions affect campaigns?
Do suppressions affect campaigns?
Yes. When sending a campaign, SendKit automatically skips any contacts on the suppression list. These contacts are not counted against your sending volume.
Does removing a suppression guarantee delivery?
Does removing a suppression guarantee delivery?
No. It only means SendKit will attempt delivery again. If the underlying problem persists (invalid mailbox, full inbox), the address may be re-suppressed automatically.
What if I'm migrating from another provider with my own suppression list?
What if I'm migrating from another provider with my own suppression list?
You can add addresses one at a time through the API. Going forward, SendKit will automatically maintain the list for you.