SMTP2GO

SMTP2GO ALLOWED SENDERS API

Manage the allowed/restricted senders list

GitHub OpenAPI

Operations 4

Each operation below carries the questions people ask an LLM about it and the instructions they give an agent to run it. Generated by API Evangelist overlay

POST /allowed_senders/add Add addresses to the allowed senders list · Add allowed senders #
Ask an LLM
“How do I add a sender domain to my allowed or restricted senders list?”
“Can I add multiple sender addresses to the senders list in one call?”
Tell an agent
Add {allowed_senders} to my Allowed Senders List.
Append {allowed_senders} to the senders list for subaccount {subaccount_id}.
POST /allowed_senders/remove Remove addresses from the allowed senders list · Remove allowed senders #
Ask an LLM
“How can I take a sender address off my allowed senders list?”
“Is it an error to remove a sender that isn't on the restricted senders list?”
Tell an agent destructive · confirm first
Remove {allowed_senders} from my Allowed Senders List.
Drop {allowed_senders} from subaccount {subaccount_id}'s senders list.
POST /allowed_senders/update Replace the senders list and its mode · Update allowed senders #
Ask an LLM
“Can I switch my senders list between whitelist, blacklist and disabled mode?”
“How do I overwrite the entire allowed senders list?”
Tell an agent
Replace my senders list with {allowed_senders} in {mode} mode.
Set subaccount {subaccount_id}'s senders list to {allowed_senders} using mode {mode}.
POST /allowed_senders/view View the allowed senders list and mode · View allowed senders #
Ask an LLM
“Which senders are on my allowed senders list and what mode is it in?”
“Is my restrict senders setting currently whitelist or blacklist?”
Tell an agent
Show my Allowed Senders List and its restrict mode.
Show the senders list for subaccount {subaccount_id}.

Documentation

📖
Documentation
https://developers.smtp2go.com/docs/introduction-guide
📖
GettingStarted
https://developers.smtp2go.com/docs/getting-started
📖
RateLimits
https://developers.smtp2go.com/docs/rate-limiting
📖
APIReference
https://developers.smtp2go.com/reference/general-api-resources

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/smtp2go/refs/heads/main/openapi/smtp2go-allowed-senders-api-openapi.yml

Other Resources

🔗
Endpoints
https://developers.smtp2go.com/docs/endpoints

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OpenAPI Specification

smtp2go-allowed-senders-api-openapi.yml Raw ↑ 
openapi: 3.2.0
info:
  title: SMTP2GO ALLOWED SENDERS API
  version: 3.0.4
  description: The SMTP2GO v3 REST API for sending transactional email and SMS, managing sender domains and single sender emails, SMTP users, API keys, IP allow lists and IP auth, templates, webhooks, suppressions, subaccounts, dedicated IPs, email archive, activity search and delivery statistics. Every operation is a POST (with a PATCH variant on two paths) carrying a JSON body; authentication is an API key supplied in the X-Smtp2go-Api-Key header or as an api_key field in the request body.
  contact:
    name: SMTP2GO Support
    url: https://support.smtp2go.com/
  termsOfService: https://www.smtp2go.com/terms/
  x-harvest:
    source: https://developers.smtp2go.com/mcp
    method: MCP tools/call get-endpoint, one call per path+method, assembled verbatim
    harvested: '2026-08-13'
    server_info:
      name: SMTP2GO-API-Docs
      version: 3.0.4
    note: SMTP2GO does not publish a single fetchable OpenAPI URL; the ReadMe registry path answers 429 to non-browser clients. The provider's own remote MCP server returns the authoritative OpenAPI 3.1.0 fragment for each endpoint anonymously, and those 73 fragments are merged here without modification.
servers:
- url: https://api.smtp2go.com/v3
  description: Regionless
- url: https://us-api.smtp2go.com/v3
  description: US Region
- url: https://eu-api.smtp2go.com/v3
  description: EU Region
- url: https://au-api.smtp2go.com/v3
  description: AU Region
security:
- sec0: []
tags:
- name: Allowed Senders
  description: Manage the allowed/restricted senders list
paths:
  /allowed_senders/add:
    post:
      tags:
      - Allowed Senders
      summary: Add allowed senders
      description: Add one or more email addresses and domain names to your Allowed or Restricted Senders List. How this list of email addresses and domain names are used is shown by the current 'mode' value; if the Restrict Senders setting is on, they will form either a whitelist or blacklist. If the setting is off, the list will be disabled. Further details of the associated setting are found in the SMTP2GO Guides. Details of how this mode can be set via the update end-point, are given further in the documentation. A post to this endpoint will return a success, even if the Restrict Senders setting is not in use.
      operationId: add-allowed-senders
      requestBody:
        content:
          application/json:
            schema:
              type: object
              required:
              - allowed_senders
              properties:
                allowed_senders:
                  type: array
                  description: Array of email addresses and domain names.
                  default:
                  - test-person@example.com
                  - other@example.com
                  items:
                    type: string
                subaccount_id:
                  type: string
                  description: If you wish to make this API call on behalf of a subaccount then include its unique ID here
      responses:
        '200':
          description: Allowed Senders list updated
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: b8f3c2b4-63ca-11ed-b66a-f23c9216ce11
                    data:
                      allowed_senders:
                      - test@test.com
                      mode: disabled
              schema:
                type: object
                required:
                - request_id
                - data
                properties:
                  request_id:
                    type: string
                    example: 40cbb6f2-935f-11e7-b5be-480fcf01a6f2
                  data:
                    type: object
                    required:
                    - allowed_senders
                    - mode
                    properties:
                      allowed_senders:
                        type: array
                        description: A list of email addresses and domain names
                        items:
                          type: string
                          example: test-person@example.com
                      mode:
                        type: string
                        description: A string indicating how the list of email address and domain names is interpreted.
                        example: whitelist
                        enum:
                        - whitelist
                        - blacklist
                        - disabled
        '400':
          description: '400'
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: 22e5acba-43bf-11e6-ae42-408d5cce2644
                    data:
                      error_code: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error: You do not have permission to access this API endpoint
              schema:
                type: object
                properties:
                  request_id:
                    type: string
                    example: 22e5acba-43bf-11e6-ae42-408d5cce2644
                  data:
                    type: object
                    properties:
                      error_code:
                        type: string
                        example: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error:
                        type: string
                        example: You do not have permission to access this API endpoint
      deprecated: false
  /allowed_senders/remove:
    post:
      tags:
      - Allowed Senders
      summary: Remove allowed senders
      description: 'Remove one or more emails addresses or domain names stored in your Allowed or Restricted Senders List. Note: In the event that any of the email addresses or domains do not feature in the list, no error will be raised.'
      operationId: remove-allowed-senders
      requestBody:
        content:
          application/json:
            schema:
              type: object
              required:
              - allowed_senders
              properties:
                allowed_senders:
                  type: array
                  description: Array of email addresses and domain names to remove.
                  default:
                  - test-person@example.com
                  items:
                    type: string
                subaccount_id:
                  type: string
                  description: If you wish to make this API call on behalf of a subaccount then include its unique ID here
      responses:
        '200':
          description: Allowed Sender Removed
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: 40cbb6f2-935f-11e7-b5be-480fcf01a6f2
                    data:
                      allowed_senders:
                      - test-person@example.com
                      mode: disabled
              schema:
                type: object
                required:
                - request_id
                - data
                properties:
                  request_id:
                    type: string
                    example: 40cbb6f2-935f-11e7-b5be-480fcf01a6f2
                  data:
                    type: object
                    required:
                    - allowed_senders
                    - mode
                    properties:
                      allowed_senders:
                        type: array
                        description: A list of email addresses and domain names
                        items:
                          type: string
                          example: test-person@example.com
                      mode:
                        type: string
                        description: A string indicating how the list of email address and domain names is interpreted.
                        example: whitelist
                        enum:
                        - whitelist
                        - blacklist
                        - disabled
        '400':
          description: '400'
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: 22e5acba-43bf-11e6-ae42-408d5cce2644
                    data:
                      error_code: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error: You do not have permission to access this API endpoint
              schema:
                type: object
                properties:
                  request_id:
                    type: string
                    example: 22e5acba-43bf-11e6-ae42-408d5cce2644
                  data:
                    type: object
                    properties:
                      error_code:
                        type: string
                        example: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error:
                        type: string
                        example: You do not have permission to access this API endpoint
      deprecated: false
  /allowed_senders/update:
    post:
      tags:
      - Allowed Senders
      summary: Update allowed senders
      description: Replace the email addresses and domain names on your Allowed or Restricted Senders List using this endpoint. How the email addresses and domain names are used is defined in the current 'mode' value - further details of these modes are found in the SMPT2GO Guides. Note that a post to this endpoint will return a success, even if the setting is not in use.
      operationId: update-allowed-senders
      requestBody:
        content:
          application/json:
            schema:
              type: object
              required:
              - allowed_senders
              - mode
              properties:
                allowed_senders:
                  type: array
                  description: Array of email addresses and domain names.
                  default:
                  - test-person@example.com
                  - other@example.com
                  items:
                    type: string
                mode:
                  type: string
                  description: A string indicating how the list of email address and domain names is interpreted. and should be one of 'whitelist', 'blacklist' or 'disabled'.<br><strong>Warning:</strong> Changing the mode to 'whitelist' or 'blacklist' disables the 'Sender Domains' and 'Single Sender Emails' features.<br>
                  default: whitelist
                  enum:
                  - whitelist
                  - blacklist
                  - disabled
                subaccount_id:
                  type: string
                  description: If you wish to make this API call on behalf of a subaccount then include its unique ID here
      responses:
        '200':
          description: Allowed Senders list updated
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: 40cbb6f2-935f-11e7-b5be-480fcf01a6f2
                    data:
                      allowed_senders:
                      - test-person@example.com
                      - otherexample.com
                      mode: whitelist
              schema:
                type: object
                required:
                - request_id
                - data
                properties:
                  request_id:
                    type: string
                    example: 40cbb6f2-935f-11e7-b5be-480fcf01a6f2
                  data:
                    type: object
                    required:
                    - allowed_senders
                    - mode
                    properties:
                      allowed_senders:
                        type: array
                        description: A list of email addresses and domain names
                        items:
                          type: string
                          example: test-person@example.com
                      mode:
                        type: string
                        description: A string indicating how the list of email address and domain names is interpreted.
                        example: whitelist
                        enum:
                        - whitelist
                        - blacklist
                        - disabled
        '400':
          description: '400'
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: 22e5acba-43bf-11e6-ae42-408d5cce2644
                    data:
                      error_code: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error: You do not have permission to access this API endpoint
              schema:
                type: object
                properties:
                  request_id:
                    type: string
                    example: 22e5acba-43bf-11e6-ae42-408d5cce2644
                  data:
                    type: object
                    properties:
                      error_code:
                        type: string
                        example: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error:
                        type: string
                        example: You do not have permission to access this API endpoint
      deprecated: false
  /allowed_senders/view:
    post:
      tags:
      - Allowed Senders
      summary: View allowed senders
      description: Returns the email addresses and domain names on your Allowed or Restricted Senders list, as well as the Restrict Senders setting, which dictates how they are interpreted.
      operationId: view-allowed-senders
      requestBody:
        content:
          application/json:
            schema:
              type: object
              required: []
              properties:
                subaccount_id:
                  type: string
                  description: If you wish to make this API call on behalf of a subaccount then include its unique ID here
      responses:
        '200':
          description: List of Allowed Senders
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: 40cbb6f2-935f-11e7-b5be-480fcf01a6f2
                    data:
                      allowed_senders:
                      - test@test.com
                      mode: disabled
              schema:
                type: object
                required:
                - request_id
                - data
                properties:
                  request_id:
                    type: string
                    example: 40cbb6f2-935f-11e7-b5be-480fcf01a6f2
                  data:
                    type: object
                    required:
                    - allowed_senders
                    - mode
                    properties:
                      allowed_senders:
                        type: array
                        description: A list of email addresses and domain names
                        items:
                          type: string
                          example: test-person@example.com
                      mode:
                        type: string
                        description: A string indicating how the list of email address and domain names is interpreted.
                        example: whitelist
                        enum:
                        - whitelist
                        - blacklist
                        - disabled
        '400':
          description: '400'
          content:
            application/json:
              examples:
                Example:
                  value:
                    request_id: 22e5acba-43bf-11e6-ae42-408d5cce2644
                    data:
                      error_code: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error: You do not have permission to access this API endpoint
              schema:
                type: object
                properties:
                  request_id:
                    type: string
                    example: 22e5acba-43bf-11e6-ae42-408d5cce2644
                  data:
                    type: object
                    properties:
                      error_code:
                        type: string
                        example: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED
                      error:
                        type: string
                        example: You do not have permission to access this API endpoint
      deprecated: false
components:
  securitySchemes:
    sec0:
      type: apiKey
      in: header
      name: X-Smtp2go-Api-Key
      x-default: ${SMTP2GO_API_KEY}