Telnyx Email Suppressions - curl

Installation

# curl is pre-installed on macOS, Linux, and Windows 10+
# jq is required for the import polling examples below:
#   macOS: brew install jq
#   Debian/Ubuntu: sudo apt-get install jq

Setup

export TELNYX_API_KEY="YOUR_API_KEY_HERE"

All examples below use $TELNYX_API_KEY for authentication and the API base URL https://api.telnyx.com/v2.

Error Handling

All API calls can fail with network errors, authentication errors (401), or framework errors (406). List-query validation failures return 400, resource lookups can return 404, and JSON body validation failures normally return 422. Inspect the HTTP status and the top-level .errors array before continuing:

response_file=$(mktemp)
status=$(curl --silent --show-error \
  --output "$response_file" \
  --write-out '%{http_code}' \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_blocks")

if [ "$status" -lt 200 ] || [ "$status" -ge 300 ]; then
  printf 'Telnyx API error (HTTP %s):\n' "$status" >&2
  jq . "$response_file" >&2
  rm -f "$response_file"
  exit 1
fi
jq . "$response_file"
rm -f "$response_file"

Common statuses are 400 malformed query or import, 401 invalid API key, 404 resource not found, 409 group still has active suppressions, 413 import too large, and 422 invalid request attributes. A successful delete may return 204 No Content; do not attempt to parse that response as JSON.

Important Notes

• Account isolation: Every lookup is scoped to the authenticated account. A malformed UUID or a UUID owned by another account is reported as 404.
• Normalized addresses: Recipient addresses are trimmed and lower-cased. The from address on a manual block is also normalized.
• Pagination: Most list operations use page[number] and page[size] (maximum 100). The main block list also supports opaque cursors. Do not combine offset and cursor modes.
• URL encoding: Percent-encode an email address placed in a URL path. For example, use alice%40example.com, not an untrusted raw string.
• Idempotency: Creating a block or adding a group suppression returns 200 when the matching suppression already exists and 201 when a row is created.

Operational Caveats

• POST /v2/email_blocks always creates reason: manual_block with source: manual. Customers cannot use this endpoint to create hard_bounce, spam_complaint, or invalid suppressions; caller-supplied reason and source are ignored.
• Scope is server-derived as account, domain, or address, never customer-set: no domain_id and no from gives account; domain_id without from gives domain; a from address gives address scope.
• unsubscribe and manual_block are overridable at send time with ignore_suppression: true. hard_bounce, spam_complaint, and invalid are not overridable. Bypassing an overridable suppression should be deliberate and auditable.
• Import is asynchronous. POST /v2/email_blocks/import returns 202 and a job ID; poll GET /v2/email_blocks/import/{id} until completed or failed. Import behavior for scoped suppressions may vary. Check the import result for the actual scope assigned.
• Export is synchronous and streams CSV directly. It does not create a job.
• Deleting a block is a soft delete: the row remains as a tombstone with status: removed. Recreating the same removed suppression reactivates it.
• The expires_at field is available for setting an expiration timestamp on suppressions.
• Check both error_count and skipped_count in the import response for rejected entries.
• A group suppression prevents sending to that address for every campaign that uses the unsubscribe group. It is not an account-wide unsubscribe for campaigns that do not use that group.

Reference Use Rules

Do not invent Telnyx parameters, enums, response fields, import counters, or CSV columns.

• Read references/api-details.md before building pagination, bulk migration, or delete automation.
• Before deciding whether a send may bypass a block, read suppression semantics.
• Before importing an exported list, read CSV export and import and verify the scope assigned by the import result.
• For exhaustive request fields, response fields, status codes, and operation IDs, use the operation catalog and response schemas.

Core Tasks

List suppressions

Use offset pagination for page-oriented tools or cursor pagination for sequential traversal without page-number offsets.

GET /v2/email_blocks

Parameter	Type	Required	Description
page[number]	integer	No	Offset page, default 1. Do not combine with a cursor.
page[size]	integer	No	1-100, default 25.
page[after]	string	No	Opaque next-page cursor. Exclusive with page[number] and page[before].
page[before]	string	No	Opaque previous-page cursor. Exclusive with page[number] and page[after].
sort	enum	No	created_at or -created_at (default).
filter[reason]	enum	No	Exact reason match.
filter[domain_id]	UUID	No	Exact domain ID match.
filter[created_after]	date-time	No	Match created_at > value.
filter[created_before]	date-time	No	Match created_at < value.

curl --get --silent --show-error \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode 'page[size]=100' \
  --data-urlencode 'filter[reason]=hard_bounce' \
  --data-urlencode 'sort=-created_at' \
  "https://api.telnyx.com/v2/email_blocks"

Offset responses expose .meta.total_pages; cursor responses expose .meta.has_next and, when another page exists, .meta.next_cursor. Pass the returned cursor unchanged.

Create a manual suppression

POST /v2/email_blocks

Parameter	Type	Required	Description
to	string	Yes	Recipient address; trimmed and lower-cased by the server.
domain_id	UUID or null	No	Domain context; omit/null for account scope.
from	string or null	No	Sender context; a value produces address scope.
expires_at	date-time or null	No	Expiration timestamp for the suppression.

curl --silent --show-error \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "blocked@example.com"
  }' \
  "https://api.telnyx.com/v2/email_blocks"

The response is .data with forced reason: manual_block, source: manual, a server-derived scope, and status: active. Do not send scope, group_id, bounce_category, dsn_code, or meta to this public operation.

Export suppressions as CSV

GET /v2/email_blocks/export

curl --get --silent --show-error \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Accept: text/csv" \
  --data-urlencode 'filter[created_after]=2026-01-01T00:00:00Z' \
  --output email_blocks_export.csv \
  "https://api.telnyx.com/v2/email_blocks/export"

The 200 response is the CSV stream itself. Filters supported by the list endpoint affect export. Although sort and page[*] are parsed and invalid values can return 400, valid values are ignored; export always streams every matching row ordered by created_at ASC, id ASC.

Start an asynchronous CSV import

POST /v2/email_blocks/import

curl --silent --show-error \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Accept: application/json" \
  -F 'file=@email_blocks.csv;type=text/csv' \
  -F 'block_ttl_days=30' \
  "https://api.telnyx.com/v2/email_blocks/import"

A valid request returns 202 with .data.id and .data.status equal to pending. CSV content may not exceed 25 MiB or 250,000 rows. Provider format is auto-detected as sendgrid, mailgun, ses, or generic. block_ttl_days applies only to imported manual_block rows.

Poll an import job

GET /v2/email_blocks/import/{id}

IMPORT_ID="00000000-0000-0000-0000-000000000000"

while :; do
  body=$(curl --silent --show-error \
    -H "Authorization: Bearer $TELNYX_API_KEY" \
    "https://api.telnyx.com/v2/email_blocks/import/$IMPORT_ID") || exit 1
  state=$(printf '%s' "$body" | jq -r '.data.status')
  printf 'import status: %s\n' "$state"
  case "$state" in
    completed)
      printf '%s' "$body" | jq '.data | {
        processed_rows, created_count, existing_count,
        skipped_count, error_count, errors
      }'
      break
      ;;
    failed)
      printf '%s' "$body" | jq '.data | {status, failure_reason}' >&2
      exit 1
      ;;
    pending|processing) sleep 2 ;;
    *) printf 'unexpected import status: %s\n' "$state" >&2; exit 1 ;;
  esac
done

Completion counters are omitted until status is completed; failure_reason is only present on failure. Check both error_count and skipped_count in the import response for rejected entries, and inspect errors when present.

Retrieve a suppression

GET /v2/email_blocks/{id}

BLOCK_ID="00000000-0000-0000-0000-000000000000"
curl --silent --show-error \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_blocks/$BLOCK_ID"

Primary response fields are .data.id, .data.to, .data.from, .data.domain_id, .data.group_id, .data.reason, .data.source, .data.scope, .data.status, .data.expires_at, .data.created_at, and .data.updated_at.

Soft-delete a suppression

DELETE /v2/email_blocks/{id}

BLOCK_ID="00000000-0000-0000-0000-000000000000"
curl --silent --show-error \
  -X DELETE \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_blocks/$BLOCK_ID"

This returns 200 with the tombstone in .data; verify .data.status == "removed". Repeating the delete is idempotent and does not append another audit event.

List a suppression's audit events

GET /v2/email_blocks/{id}/events

BLOCK_ID="00000000-0000-0000-0000-000000000000"
curl --get --silent --show-error \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode 'page[number]=1' \
  --data-urlencode 'page[size]=50' \
  "https://api.telnyx.com/v2/email_blocks/$BLOCK_ID/events"

Events are newest first and can be created, removed, expired, or override_used. This endpoint has offset pagination only and a default page size of 50; it has no filters, sort, or cursor parameters.

List unsubscribe groups

GET /v2/email_unsubscribe_groups

curl --get --silent --show-error \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode 'page[number]=1' \
  --data-urlencode 'page[size]=25' \
  "https://api.telnyx.com/v2/email_unsubscribe_groups"

Groups use offset pagination only and fixed newest-first ordering.

Create an unsubscribe group

POST /v2/email_unsubscribe_groups

curl --silent --show-error \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Product announcements",
    "description": "Optional opt-out category for product email"
  }' \
  "https://api.telnyx.com/v2/email_unsubscribe_groups"

name is required, non-empty, and at most 255 characters. A successful create returns 201 and the group in .data.

Retrieve an unsubscribe group

GET /v2/email_unsubscribe_groups/{id}

GROUP_ID="00000000-0000-0000-0000-000000000000"
curl --silent --show-error \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_unsubscribe_groups/$GROUP_ID"

Update an unsubscribe group

Only name and description are mutable. This is a partial update; PUT is not routed.

PATCH /v2/email_unsubscribe_groups/{id}

GROUP_ID="00000000-0000-0000-0000-000000000000"
curl --silent --show-error \
  -X PATCH \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "description": "Announcements and release notes"
  }' \
  "https://api.telnyx.com/v2/email_unsubscribe_groups/$GROUP_ID"

Delete an unsubscribe group

DELETE /v2/email_unsubscribe_groups/{id}

GROUP_ID="00000000-0000-0000-0000-000000000000"
curl --silent --show-error \
  -X DELETE \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_unsubscribe_groups/$GROUP_ID"

A successful delete returns 204. If active group suppressions remain, the request returns 409. Either remove them first or deliberately force the delete:

curl --get --silent --show-error \
  -X DELETE \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode 'force=true' \
  "https://api.telnyx.com/v2/email_unsubscribe_groups/$GROUP_ID"

force=true soft-deletes active group suppressions, clears their group links, appends removal events, and then hard-deletes the group in one transaction.

List suppressions in a group

GET /v2/email_unsubscribe_groups/{id}/suppressions

GROUP_ID="00000000-0000-0000-0000-000000000000"
curl --get --silent --show-error \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode 'page[number]=1' \
  --data-urlencode 'page[size]=100' \
  "https://api.telnyx.com/v2/email_unsubscribe_groups/$GROUP_ID/suppressions"

Rows use the standard email-block shape with .group_id set to this group. This list supports offset pagination only; no filters, sort, or cursor.

Add a group suppression

POST /v2/email_unsubscribe_groups/{id}/suppressions

GROUP_ID="00000000-0000-0000-0000-000000000000"
curl --silent --show-error \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "subscriber@example.com"
  }' \
  "https://api.telnyx.com/v2/email_unsubscribe_groups/$GROUP_ID/suppressions"

Only to is read. The server forces reason: unsubscribe, source: manual, and this group's group_id. A duplicate is idempotent and returns 200.

Remove a group suppression

DELETE /v2/email_unsubscribe_groups/{id}/suppressions/{email}

GROUP_ID="00000000-0000-0000-0000-000000000000"
# The email path segment is percent-encoded.
EMAIL_PATH="subscriber%40example.com"
curl --silent --show-error \
  -X DELETE \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_unsubscribe_groups/$GROUP_ID/suppressions/$EMAIL_PATH"

A successful removal returns 204 and soft-deletes every active matching row for the normalized address in that group. A repeat returns 404 because no active matching group suppression remains.

Webhooks

Email webhooks are configured at the domain level, not on an individual suppression. Create a subscription with POST /email_domains/{id}/webhooks using the https://api.telnyx.com/v2 base URL. The suppression-related event names in the current OpenAPI EmailWebhookEvent enum are:

Event	Use in a suppression workflow
email.bounced	Process a bounced-delivery outcome.
email.failed	Process a terminal delivery failure.
email.complained	Process a recipient complaint.
email.unsubscribed	Process a recipient unsubscribe action.

DOMAIN_ID="00000000-0000-0000-0000-000000000000"
curl --silent --show-error \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://example.com/webhooks/email",
    "events": ["email.bounced", "email.failed", "email.complained", "email.unsubscribed"]
  }' \
  "https://api.telnyx.com/v2/email_domains/$DOMAIN_ID/webhooks"

Verify signatures before parsing

Telnyx signs webhook requests with Ed25519. Read the telnyx-signature-ed25519 and telnyx-timestamp headers, and retain the exact raw request body bytes. Do not parse or re-serialize the JSON before verification.

1. Reject a missing or malformed timestamp, signature, or body.
2. Reject a timestamp more than 5 minutes outside the server clock.
3. Verify the Ed25519 signature over telnyx-timestamp + "|" + raw_body with the Telnyx public key. Ed25519 verification is not HMAC validation.
4. Parse the JSON only after the signature and timestamp are valid.

Deduplicate and acknowledge quickly

• Deduplicate by event ID with an atomic uniqueness check before applying side effects. Treat an already-seen event as successfully handled.
• Enqueue slow work and return a 2xx response within 10 seconds.
• Telnyx retries on timeout or non-2xx. Keep your endpoint idempotent.

Additional Operations

Use the core tasks above first. All 16 reachable suppression and unsubscribe group operations are indexed here with their exact HTTP endpoints. Use references/api-details.md for full optional parameters, response schemas, status codes, and operation IDs.

Operation	SDK method	Endpoint	Use when	Required params
List suppressions	HTTP only	GET /email_blocks	Inspect suppressions or select a block before another action.	None
Create a manual suppression	HTTP only	POST /email_blocks	Add a manual recipient suppression.	to
Export suppressions as CSV	HTTP only	GET /email_blocks/export	Download matching suppressions as CSV.	None
Start a CSV import	HTTP only	POST /email_blocks/import	Upload suppressions for asynchronous import.	file
Poll an import job	HTTP only	GET /email_blocks/import/{id}	Check whether an asynchronous import completed or failed.	id
Retrieve a suppression	HTTP only	GET /email_blocks/{id}	Fetch one suppression by ID.	id
Soft-delete a suppression	HTTP only	DELETE /email_blocks/{id}	Remove an existing suppression.	id
List suppression audit events	HTTP only	GET /email_blocks/{id}/events	Inspect the history of one suppression.	id
List unsubscribe groups	HTTP only	GET /email_unsubscribe_groups	Inspect available unsubscribe groups.	None
Create an unsubscribe group	HTTP only	POST /email_unsubscribe_groups	Create a campaign-level unsubscribe category.	name
Retrieve an unsubscribe group	HTTP only	GET /email_unsubscribe_groups/{id}	Fetch one unsubscribe group by ID.	id
Update an unsubscribe group	HTTP only	PATCH /email_unsubscribe_groups/{id}	Change a group's name or description.	id
Delete an unsubscribe group	HTTP only	DELETE /email_unsubscribe_groups/{id}	Remove an unsubscribe group.	id
List group suppressions	HTTP only	GET /email_unsubscribe_groups/{id}/suppressions	Inspect recipients suppressed in one group.	id
Add a group suppression	HTTP only	POST /email_unsubscribe_groups/{id}/suppressions	Suppress a recipient in one unsubscribe group.	id, to
Remove a group suppression	HTTP only	DELETE /email_unsubscribe_groups/{id}/suppressions/{email}	Remove a recipient suppression from one group.	id, email

---

For exhaustive parameter behavior, CSV columns and limitations, response schemas, status codes, and operation IDs, see references/api-details.md.