openapi: 3.2.0 info: title: SMTP2GO SINGLE SENDER EMAILS 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: SINGLE SENDER EMAILS description: Verify individual From addresses paths: /single_sender_emails/add: post: tags: - SINGLE SENDER EMAILS summary: Add a single sender email description: Use the API to add a single sender email address to your account, to use from which to send mail. If the email address has previously been added and not yet verified, this action will simply resend the verification email. operationId: add-a-single-sender-email requestBody: content: application/json: schema: type: object required: - email_address properties: email_address: type: string description: The email address that you wish to send emails from default: send@example.com message: type: string description: (Optional) If provided, will add a text only message to the email. 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: Single sender email added content: application/json: examples: Result: value: just_returns_this: ok schema: type: object required: - request_id properties: request_id: type: string example: e023461c-8c86-11e9-b984-408d5cce2644 '400': description: '400' content: application/json: examples: Result: value: request_id: 22e5acba-43bf-11e6-ae42-408d5cce2644 data: error: You do not have permission to access this API endpoint error_code: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED schema: type: object properties: request_id: type: string example: 22e5acba-43bf-11e6-ae42-408d5cce2644 data: type: object properties: error: type: string example: You do not have permission to access this API endpoint error_code: type: string example: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED deprecated: false /single_sender_emails/remove: post: tags: - SINGLE SENDER EMAILS summary: Remove a single sender email description: Remove a single sender email address from your account. Include the address to remove as the email_address parameter. operationId: remove-a-single-sender-email requestBody: content: application/json: schema: type: object required: - email_address properties: email_address: type: string description: The email address to remove from your Single Sender Emails default: send@example.com 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: Single sender email removed content: application/json: examples: Result: value: just_returns_this: OK schema: type: object required: - request_id properties: request_id: type: string example: 22e5acba-43bf-11e6-ae42-408d5cce2644 data: type: string '400': description: '400' content: application/json: examples: Result: value: request_id: 22e5acba-43bf-11e6-ae42-408d5cce2644 data: error: You do not have permission to access this API endpoint error_code: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED schema: type: object properties: request_id: type: string example: 22e5acba-43bf-11e6-ae42-408d5cce2644 data: type: object properties: error: type: string example: You do not have permission to access this API endpoint error_code: type: string example: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED deprecated: false /single_sender_emails/view: post: tags: - SINGLE SENDER EMAILS summary: View single sender emails description: Returns a list of single sender email addresses on your account, along with their verification status. If you include a email_address, the response will only include items matching this search. operationId: view-all-single-sender-emails requestBody: content: application/json: schema: type: object properties: email_address: type: string description: (Optional) If provided, only return email addresses that match value 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 single sender emails content: application/json: examples: Result: value: data: request_id: e023461c-8c86-11e9-b984-408d5cce2644 senders: - email_address: test@test.com verified: true schema: type: object properties: data: type: object required: - request_id - senders properties: request_id: type: string example: e023461c-8c86-11e9-b984-408d5cce2644 senders: type: array items: type: object required: - email_address - verified properties: email_address: type: string example: test@test.com verified: type: boolean example: true default: true '400': description: '400' content: application/json: examples: Result: value: request_id: 22e5acba-43bf-11e6-ae42-408d5cce2644 data: error: You do not have permission to access this API endpoint error_code: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED schema: type: object properties: request_id: type: string example: 22e5acba-43bf-11e6-ae42-408d5cce2644 data: type: object properties: error: type: string example: You do not have permission to access this API endpoint error_code: type: string example: E_ApiResponseCodes.ENDPOINT_PERMISSION_DENIED deprecated: false components: securitySchemes: sec0: type: apiKey in: header name: X-Smtp2go-Api-Key x-default: ${SMTP2GO_API_KEY}