team-telnyx/telnyx-email-curl

Telnyx Email - curl

Installation

# curl is pre-installed on macOS, Linux, and Windows 10+
# jq is required for examples that capture IDs from responses:
#   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.

Error Handling

All API calls can fail with network errors, rate limits (429), validation errors (400 or 422), or authentication errors (401). Preserve the response body so the Telnyx error code and detail remain available:

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": {"email": "[email protected]", "name": "Example"},
    "to": ["[email protected]"],
    "subject": "Hello from Telnyx",
    "text_body": "Your notification is ready."
  }' \
  "https://api.telnyx.com/v2/email_messages"

Common errors: 401 invalid credentials, 403 sender-domain eligibility or verification failure, 404 resource not found, 413 body larger than 8,000,000 bytes, and 422 semantic validation or template-rendering failure. A 429 is not necessarily a transient throughput limit: it can indicate a reputation suspension or a daily policy limit. Inspect .errors[0].code and .errors[0].detail before deciding whether to retry. See the full taxonomy in references/api-details.md.

Important Notes

• Base URL: All paths in this skill are relative to https://api.telnyx.com/v2.
• Sender domain: The domain in from.email must be authorized and ready for sending. A successful create response means accepted, queued, scheduled, or sandbox-created—not delivered.
• Address input: from, reply_to, and each to/cc/bcc item accept either a string address or { "email": "...", "name": "..." }. Recipients must be unique across to, cc, and bcc after case-insensitive normalization.
• Body or template: subject is required unless template_id is supplied. With template_id, do not also send subject, html_body, or text_body; pass Liquid values in template_variables.
• Pagination: Core Email endpoints use page_size (default 25, maximum 100) and the opaque page_cursor returned in .meta.page_cursor. Do not translate these names to page[size] or page[cursor].
• Message listing: GET /email_messages currently implements cursor pagination only; no message filters are exposed. Event and recipient list endpoints have their own filters.

Operational Caveats

• Scheduling is fail-open: scheduled_at is the preferred field. If it is invalid or in the past, the API silently sends immediately. Validate the timestamp before sending and confirm the response status is scheduled when future delivery is required. The legacy send_at alias remains accepted; if both are present, scheduled_at wins.
• Batch status: POST /email_messages/batch always returns 207 Multi-Status, including when every item succeeds. It does not return 202.
• Batch limit: A batch contains 1–50 messages. Split larger jobs and give each request its own idempotency key.
• Idempotency is endpoint-specific: Idempotency-Key is supported only on POST /email_messages, POST /email_messages/batch, POST /email_templates, POST /email_validations, and POST /email_validations/batch. Do not send it universally.
• Sandbox behavior: sandbox_mode: true skips Kafka/MTA delivery, but still persists the message, emits a sandbox event, and creates a non-billable Email Detail Record (EDR). Batch-level sandbox_mode overrides every per-message value.
• 429 requires classification: It can mean reputation suspension or a daily policy limit. Read the error code/detail; do not blindly back off and retry an account-policy failure.
• Attachments are in-band JSON: Put attachment content in the request as a Base64 string. disposition: "inline" plus content_id supports CID references. The whole request body is limited to 8,000,000 bytes (approximately 8 MB), including Base64 overhead.
• Tags are not labels: Outbound tags are immutable billing/reporting attribution propagated to EDRs and Mission Control. Mailbox labels are mutable workflow state and are a different concept.
• Threading is single-send only: in_reply_to_message_id, reply_to_all, and forward_of_message_id are accepted by single send but not by batch send. in_reply_to_message_id and forward_of_message_id are mutually exclusive.

Reference Use Rules

Do not invent Telnyx parameters, enums, response fields, or webhook fields.

• If a parameter, enum, or response field is not shown inline, read references/api-details.md before writing the request or handler.
• Before using an operation in ## Additional Operations, read the parameter reference and the response schemas.
• Before matching webhook fields or event names, read the webhook payload reference. Pollable and subscribable event enums are intentionally different.
• Treat the two delete-message routes marked not yet available as unreachable even though they appear in the OpenAPI contract.

Core Tasks

Send an email

Primary outbound transactional-email flow.

POST /v2/email_messages

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | from | string or email-address object | Yes | Sender address; object form supports email and optional name. | | to | array[string or email-address object] | Yes | At least one recipient. Must be unique across all recipient lists. | | from_name | string | No | Display name for string from; overrides from.name. | | cc | array[string or object] | No | Carbon-copy recipients. | | bcc | array[string or object] | No | Blind-copy recipients. | | reply_to | string or object | No | Reply-to address; an object name is ignored when stored. | | subject | string | Conditional | Required without template_id. Do not use with a template. | | html_body | string | No | HTML body. Returned only by the message detail endpoint. | | text_body | string | No | Plain-text body. Returned only by the message detail endpoint. | | headers | object[string,string] | No | Custom headers; write-only. | | attachments | array[attachment] | No | Embedded Base64 attachment objects. | | tags | array[string] | No | Immutable EDR/reporting attribution; not returned by the API. | | group_id | UUID or null | No | Unsubscribe group for suppression checks. | | ignore_suppression | boolean | No | Default false; requires email:override scope and cannot override hard-bounce, complaint, or invalid-address suppressions. | | metadata | object | No | Custom write-only metadata. | | tracking_settings | object | No | open_tracking and/or click_tracking; omitted values inherit domain settings. | | template_id | UUID | No | Liquid template ID. Makes subject/body fields mutually exclusive. | | template_variables | object | No | Liquid values; defaults to {}. | | scheduled_at | date-time or null | No | Preferred future send time; invalid/past values send immediately. | | send_at | date-time | No | Deprecated alias for scheduled_at. | | inline_css | boolean | No | Inline CSS before sending; default false. | | sandbox_mode | boolean | No | Persist and emit sandbox records without MTA delivery; default false. | | in_reply_to_message_id | UUID or null | No | Parent Telnyx message; adds RFC 5322 threading headers. | | reply_to_all | boolean or null | No | Reply-all intent; meaningful only with in_reply_to_message_id. | | forward_of_message_id | UUID or null | No | Forward provenance; mutually exclusive with in_reply_to_message_id. | | Idempotency-Key | header string | No | 1–255 letters, digits, _, or -; reuse only for the identical retry. |

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: 8e03978e-40d5-43e8-bc93-6894a57f9326" \
  -d '{
    "from": {"email": "[email protected]", "name": "Example Orders"},
    "to": [{"email": "[email protected]", "name": "Customer"}],
    "subject": "Order received",
    "html_body": "<p>Thanks for your order.</p>",
    "text_body": "Thanks for your order.",
    "tags": ["order-confirmation"],
    "tracking_settings": {"open_tracking": true, "click_tracking": true}
  }' \
  "https://api.telnyx.com/v2/email_messages"

Primary response fields:

• .data.id, .data.status, .data.from, .data.to, .data.cc, .data.bcc
• .data.subject, .data.template_id, .data.attachments, .data.events
• .data.created_at, optional .data.scheduled_at, .data.sandbox, and .data.recipient_statuses
• optional top-level .suppressed[] when some recipients were removed but at least one remains

Send a batch

Send 1–50 independent messages. Always parse both success and error arrays from the 207 response.

POST /v2/email_messages/batch

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | messages | array[message] | Yes | 1–50 items; each has the single-send shape except the three threading fields. | | sandbox_mode | boolean | No | Applies to every item and overrides item-level sandbox_mode. | | Idempotency-Key | header string | No | Idempotency for the whole batch request. |

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: d6aa99f9-df20-4caf-99aa-e4c8b67e80ef" \
  -d '{
    "messages": [
      {
        "from": "[email protected]",
        "to": ["[email protected]"],
        "subject": "Alert one",
        "text_body": "First alert"
      },
      {
        "from": "[email protected]",
        "to": ["[email protected]"],
        "subject": "Alert two",
        "text_body": "Second alert"
      }
    ]
  }' \
  "https://api.telnyx.com/v2/email_messages/batch"

Primary response fields:

• .data[] — successful EmailMessage objects
• .errors[] — failed items with zero-based index, code, and message
• .meta.total, .meta.succeeded, .meta.failed

Schedule and cancel an email

Scheduling uses the normal create endpoint. Confirm .data.status == "scheduled"; an invalid or past timestamp is silently treated as an immediate send.

# Schedule for a future time (compute dynamically so the value is always in the future)
SCHEDULED_AT=$(date -u -v+1H '+%Y-%m-%dT%H:%M:%SZ' 2>/dev/null || date -u -d '+1 hour' '+%Y-%m-%dT%H:%M:%SZ')

# Capture the scheduled message ID for cancellation below
EMAIL_ID=$(curl -s --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "[email protected]",
    "to": ["[email protected]"],
    "subject": "Appointment reminder",
    "text_body": "Your appointment is tomorrow.",
    "scheduled_at": "'$SCHEDULED_AT'"
  }' \
  "https://api.telnyx.com/v2/email_messages" | jq -r '.data.id')

Cancel only while the message is still scheduled:

DELETE /v2/email_messages/{email_id}/schedule

curl --fail-with-body \
  -X DELETE \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_messages/$EMAIL_ID/schedule"

The cancel response is an EmailMessageResponse whose .data.status is cancelled.

List and retrieve messages

GET /v2/email_messages uses newest-first cursor pagination and has no filters. GET /v2/email_messages/{id} returns the detail shape, including bodies.

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | page_size | integer 1–100 | No | Defaults to 25; invalid values are clamped. | | page_cursor | string | No | Opaque URL-safe Base64 cursor from the preceding response. | | id | UUID path | For get | Email message ID. |

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode "page_size=25" \
  --data-urlencode "page_cursor=$PAGE_CURSOR" \
  "https://api.telnyx.com/v2/email_messages"

curl --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_messages/$EMAIL_ID"

The detail response adds .data.text_body and .data.html_body. Continue pagination only when .meta.page_cursor is present.

---

Webhook Verification

Telnyx signs webhook requests with Ed25519 using the telnyx-signature-ed25519 and telnyx-timestamp headers.

# Verify the signature against: telnyx-timestamp + "|" + the exact raw body.
# Do not parse/re-serialize JSON before verification.
# Reject timestamps more than 5 minutes outside your server clock.
# Deduplicate by event ID, then enqueue work and return 2xx quickly.
# Ed25519 is asymmetric signature verification; it is not HMAC.

Webhooks

Outbound lifecycle normally progresses:

email.queued → email.sending → email.sent → email.delivered

Terminal alternatives include email.bounced and email.failed; deferred, complaint, engagement, unsubscribe, sandbox, and scheduled events may also occur.

Email webhooks are configured per sender domain—not per message—using POST /v2/email_domains/{domain_id}/webhooks. A message-send request has no webhook_url parameter.

Telnyx retries webhook deliveries on timeout or non-2xx responses. Keep your endpoint idempotent — the same event may be delivered multiple times. Return 2xx within 10 seconds to acknowledge receipt.

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://example.net/webhooks/email",
    "events": ["email.sent", "email.delivered", "email.bounced", "email.failed"]
  }' \
  "https://api.telnyx.com/v2/email_domains/$DOMAIN_ID/webhooks"

The webhook subscription enum is not the pollable event enum. In particular, cancelled, daily_limit_exceeded, and system/gateway rejection events can be pollable without being subscribable webhooks. Conversely, subscriptions use email.* names while polling uses unprefixed values such as delivered. Read the complete enum and payload reference before writing event dispatch code.

---

Important Supporting Operations

Use these when the core send flow needs a follow-up, reusable content, reporting, or pre-send address checks.

Inspect message events and recipient states

| Operation | Endpoint | Optional query parameters | |-----------|----------|---------------------------| | List one message's events | GET /v2/email_messages/{email_id}/events | page_size, page_cursor | | List one message's recipients | GET /v2/email_messages/{email_id}/recipients | page_size, page_cursor, status, kind | | Get one recipient | GET /v2/email_messages/{email_id}/recipients/{recipient_id} | None |

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode "page_size=25" \
  --data-urlencode "page_cursor=$PAGE_CURSOR" \
  "https://api.telnyx.com/v2/email_messages/$EMAIL_ID/events"

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode "status=bounced" \
  --data-urlencode "kind=to" \
  "https://api.telnyx.com/v2/email_messages/$EMAIL_ID/recipients"

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_messages/$EMAIL_ID/recipients/$RECIPIENT_ID"

Recipient status values are queued, sending, sent, deferred, delivered, bounced, failed, gw_reject, and cancelled. Each recipient has its own billable flag and SMTP outcome. BCC addresses are returned as null.

Create, manage, and render templates

Templates use Liquid. Create requires only name; subject and bodies may be null, and variables are auto-extracted when omitted.

| Operation | Endpoint | Body or query | |-----------|----------|---------------| | Create | POST /v2/email_templates | name; optional subject, html_body, text_body, variables | | List | GET /v2/email_templates | optional page_size, page_cursor | | Get | GET /v2/email_templates/{id} | None | | Replace | PUT /v2/email_templates/{id} | Any template fields; despite the name, behaves identically to PATCH | | Update | PATCH /v2/email_templates/{id} | One or more template fields | | Delete | DELETE /v2/email_templates/{id} | None; success is 204 with no body | | Render | POST /v2/email_templates/{id}/render | optional template_variables; defaults to {} |

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: 91f8e70a-9ca0-43c7-b77c-594935493637" \
  -d '{
    "name": "order-confirmation",
    "subject": "Order {{ order_id }} received",
    "html_body": "<p>Hello {{ customer_name }}</p>"
  }' \
  "https://api.telnyx.com/v2/email_templates"

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode "page_size=25" \
  --data-urlencode "page_cursor=$PAGE_CURSOR" \
  "https://api.telnyx.com/v2/email_templates"

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_templates/$TEMPLATE_ID"

curl --fail-with-body \
  -X PUT \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "order-confirmation-v2",
    "subject": "Order {{ order_id }} confirmed"
  }' \
  "https://api.telnyx.com/v2/email_templates/$TEMPLATE_ID"

curl --fail-with-body \
  -X PATCH \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"subject":"Order {{ order_id }} is confirmed"}' \
  "https://api.telnyx.com/v2/email_templates/$TEMPLATE_ID"

curl --fail-with-body \
  -X DELETE \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_templates/$TEMPLATE_ID"

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"template_variables":{"order_id":"A-100","customer_name":"Ada"}}' \
  "https://api.telnyx.com/v2/email_templates/$TEMPLATE_ID/render"

List account events and statistics

GET /v2/email_events lists account events oldest first. It accepts event_type as comma-separated or repeated parameters, plus email_id, from, and to. GET /v2/email_events/stats accepts from and to and returns recipient-level counts and rates.

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode "event_type=delivered,bounced" \
  --data-urlencode "from=2026-07-01T00:00:00Z" \
  --data-urlencode "to=2026-07-31T23:59:59Z" \
  "https://api.telnyx.com/v2/email_events"

curl --get --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  --data-urlencode "from=2026-07-01T00:00:00Z" \
  --data-urlencode "to=2026-07-31T23:59:59Z" \
  "https://api.telnyx.com/v2/email_events/stats"

When from is omitted it defaults to 30 days ago. If from is present without to, the end defaults to from + 30 days.

Validate email addresses

Single validation is synchronous. Batch validation accepts 1–1,000 addresses, deduplicates them, and returns an asynchronous job to poll.

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"[email protected]"}' \
  "https://api.telnyx.com/v2/email_validations"

curl --fail-with-body \
  -X POST \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "emails":["[email protected]","[email protected]"],
    "webhook_url":"https://example.net/webhooks/validation-complete"
  }' \
  "https://api.telnyx.com/v2/email_validations/batch"

curl --fail-with-body \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  "https://api.telnyx.com/v2/email_validations/batch/$BATCH_ID"

Poll until .data.status is completed or failed; completed results are in .data.results, keyed by the original address.

---

Additional Operations

The 20 operations below are reachable. Use the core tasks above first, then consult references/api-details.md for every optional parameter and full response shape. There are no curl SDK methods: use the raw HTTP method and path shown here.

| Operation | HTTP method | Endpoint | Use when | Required params | |-----------|-------------|----------|----------|-----------------| | Send, schedule, or sandbox an email | POST | /v2/email_messages | Create one outbound message. | from, to; subject unless template_id | | Send a batch | POST | /v2/email_messages/batch | Create up to 50 messages and parse per-item outcomes. | messages | | List messages | GET | /v2/email_messages | Page through account messages. | None | | Get a message | GET | /v2/email_messages/{id} | Retrieve bodies and current state. | id | | Cancel a scheduled message | DELETE | /v2/email_messages/{email_id}/schedule | Stop a message that is still scheduled. | email_id | | List message events | GET | /v2/email_messages/{email_id}/events | Poll one message's lifecycle. | email_id | | List message recipients | GET | /v2/email_messages/{email_id}/recipients | Inspect per-recipient outcomes. | email_id | | Get one message recipient | GET | /v2/email_messages/{email_id}/recipients/{recipient_id} | Inspect one recipient's SMTP state. | email_id, recipient_id | | Create a template | POST | /v2/email_templates | Store reusable Liquid content. | name | | List templates | GET | /v2/email_templates | Select or audit templates. | None | | Get a template | GET | /v2/email_templates/{id} | Retrieve one template. | id | | Replace a template | PUT | /v2/email_templates/{id} | Compatibility update; behaves like PATCH. | id | | Update a template | PATCH | /v2/email_templates/{id} | Modify selected template fields. | id | | Delete a template | DELETE | /v2/email_templates/{id} | Remove reusable content. | id | | Render a template | POST | /v2/email_templates/{id}/render | Preview Liquid output. | id | | List account events | GET | /v2/email_events | Query pollable lifecycle/engagement events. | None | | Get event statistics | GET | /v2/email_events/stats | Compute recipient-level counts and rates. | None | | Validate one address | POST | /v2/email_validations | Synchronously assess deliverability. | email | | Create a validation batch | POST | /v2/email_validations/batch | Validate up to 1,000 addresses asynchronously. | emails | | Get a validation batch | GET | /v2/email_validations/batch/{id} | Poll batch status and retrieve results. | id |

Not yet available

These OpenAPI operations are not routed in the deployed API. Do not call them or count them among the 20 reachable operations:

| Operation | Endpoint | Status | |-----------|----------|--------| | Delete all account email data matching an address | DELETE /v2/email_messages?address=... | Not yet available | | Delete one email message and retained child data | DELETE /v2/email_messages/{id} | Not yet available |

---

For exhaustive operation parameters, complete response schemas, webhook fields, and error codes, see references/api-details.md.