SendMailOS resources
Use the API, SMTP or a compatible MCP assistant. Every option below explains how it connects and where to start.
Send application email from your backend with standard HTTPS requests. Create a scoped key, verify the From domain and keep the secret on your server.
Use a test-mode key during development. Reuse the same idempotency key when retrying the same request. A 202 response means accepted for processing; inspect status or delivery events for the outcome.
Follow the API quickstartConnect an app that supports configurable SMTP ports and TLS. Create a sending-only SMTP password for the verified domain; use a separate password for each application.
Host: smtp.sendmailos.com. Username: sendmailos. Use port 2525 with STARTTLS or 2465 with implicit TLS. SMTP attachments are currently rejected.
Connect a compatible remote MCP client to create and edit structured email templates. Sign in through OAuth and approve the organizations and permissions shown.
Use https://dash.sendmailos.com/api/mcp. Revoke access from Connected Apps. Template MCP does not send campaigns or modify workflows.
Connect an HTTPS receiver for email and reply events. Verify the raw-body signature and handle retries without processing the same event twice.
New endpoints remain inactive until they pass the signed verification challenge. Changing the endpoint URL requires verification again.
Build a webhook receiverUse a WordPress mail plugin with an Other SMTP option that supports ports 2525 or 2465. Set a permitted verified-domain From address and force it when other plugins override it.
For contact forms, keep your own domain in From and use the visitor address in Reply-To. This is generic SMTP configuration, not the native SendMailOS WordPress plugin.
Configure a WordPress mail pluginConnect application conversations with SendMailOS threads and incoming-message events. Configure supported receiving and reply capture before relying on replies in your application.
Use your actual order or booking identifier in your own integration. Check the receiving configuration and permissions in a controlled conversation test.
Review reply-capture setup helpAPI integration means your developer builds against the documented API. SMTP configuration means an existing app connects using SMTP settings. OAuth + MCP means a compatible assistant connects through the supported authorization flow.
We do not list an app as a native integration solely because it can make HTTP requests. The dedicated SendMailOS WordPress plugin is not listed as a released integration here. Shopify, WooCommerce and automation-platform connectors are not presented as shipped without a verified setup path.
Questions and answers
No. The directory labels API integrations, SMTP configuration and OAuth + MCP connections separately. A generic API or SMTP setup is not presented as a native plugin.
The application must support the required authentication, TLS mode and custom port. SendMailOS currently uses 2525 for STARTTLS and 2465 for implicit TLS. Applications restricted to standard ports need a different supported connection path.
SMTP attachments are currently rejected. The HTTP API supports attachments on SES-routed domains; review the current documentation and your selected sending route before implementing attachment sends.
No. The connected server is a delivery route. Campaigns, contacts, templates and reports remain in SendMailOS. Review the server setup and the platform data-handling information before choosing your architecture.
Prepare your audience, connect your application, or create an editable email design.