Never send to a known bad address again

Keep one suppression list for your workspace. Import it, export it, and check it before each send.

Get started free Delivery feedback

Fig. 1Three sources, one list

Sources: Events, checks, imports, your team
Reasons: 7
Lookup: GET /v1/suppressions/check
Files: CSV import and export

§ 1

Why it matters

Suppressions get lost between tools

Each email platform keeps its own list. When you switch tools or import a new file, old bounces come back.

Bounces, complaints, unsubscribes, and invalid results all end up in one place.

Fig. 2Without and with Verifier

WithoutWith Verifier

Without: Each tool keeps its own do-not-send list.With Verifier: One list for the workspace, from events, checks, and your team.
Without: A removed address comes back with the next import.With Verifier: One call tells you if an address is suppressed.
Without: Nobody knows why an address was blocked.With Verifier: Each entry keeps its reason and its history.

§ 2

How it works

One list, many sources

Add suppressions by hand, by import, from invalid results, or from delivery feedback. Each entry keeps its reason and its history.

2.1Import your current suppression list.
2.2Let invalid results and delivery feedback add new entries.
2.3Check addresses against the list before each send, or export it to your email platform.

Fig. 3Ask before you send

Request

GET /v1/suppressions/[email protected]

Response

{  "suppressed": true,  "reason": "bounce",  "source": "sendgrid",  "created_at": "2026-10-16T09:12:44Z"}

Fields trimmed

§ 3

What you get

What you get.

3.1Reasons and historyEach entry records why it was suppressed: bounce, complaint, unsubscribe, spam trap, invalid, or manual.
3.2Check before you sendCheck an address against the list in the app or through the API.

Table 3 · Suppression reasons

Reason	How the address got on the list
bounce	Your email platform reported a bounce.
complaint	The recipient marked a message as spam.
unsubscribe	The recipient unsubscribed.
invalid	A check found the address invalid.
auto_invalid	Added after a check, from your workspace settings.
spam_trap	The address is at a known spam-trap domain.
manual	Someone on your team added it, or imported a file.

§ 4

In practice

Typical uses.

Case 4.1
Switching email platforms
Bring your suppressions with you when you move to a new platform.

Works with the tools you send from.

All integrations

Questions

Before you start.

Can I remove an entry?

Yes. Removing an entry is recorded in its history.

Suppressions get lost between tools

Each email platform keeps its own list. When you switch tools or import a new file, old bounces come back.

Bounces, complaints, unsubscribes, and invalid results all end up in one place.

Fig. 2Without and with Verifier

WithoutWith Verifier

Without: Each tool keeps its own do-not-send list.With Verifier: One list for the workspace, from events, checks, and your team.
Without: A removed address comes back with the next import.With Verifier: One call tells you if an address is suppressed.
Without: Nobody knows why an address was blocked.With Verifier: Each entry keeps its reason and its history.

One list, many sources

Add suppressions by hand, by import, from invalid results, or from delivery feedback. Each entry keeps its reason and its history.

2.1Import your current suppression list.
2.2Let invalid results and delivery feedback add new entries.
2.3Check addresses against the list before each send, or export it to your email platform.

Fig. 3Ask before you send

Request

GET /v1/suppressions/[email protected]

Response

{  "suppressed": true,  "reason": "bounce",  "source": "sendgrid",  "created_at": "2026-10-16T09:12:44Z"}

Fields trimmed

What you get.

3.1Reasons and historyEach entry records why it was suppressed: bounce, complaint, unsubscribe, spam trap, invalid, or manual.

3.2Check before you sendCheck an address against the list in the app or through the API.

Table 3 · Suppression reasons

Reason	How the address got on the list
bounce	Your email platform reported a bounce.
complaint	The recipient marked a message as spam.
unsubscribe	The recipient unsubscribed.
invalid	A check found the address invalid.
auto_invalid	Added after a check, from your workspace settings.
spam_trap	The address is at a known spam-trap domain.
manual	Someone on your team added it, or imported a file.

From a raw listto a safe send.

Never send to a known bad address again

Suppressions get lost between tools

One list, many sources

What you get.

Typical uses.

Works with the tools you send from.

Before you start.

From a raw listto a safe send.

Never send to a known bad address again

Suppressions get lost between tools

One list, many sources

What you get.

Typical uses.

Works with the tools you send from.

Before you start.