Submit a controlled message through SMTP.com v4
Use the current v4 sending model and inspect the JSend application result before treating an HTTP exchange as successful submission.
Reviewed
Use the sending operation/client linked by SMTP.com’s v4 reference. Match the request to the actual sender/channel configuration; do not combine an older SMTP credential example with a v4 JSON request.
Prepare one approved submission
- Load the API key securely and configure a supported header-based authentication method.
- Select the intended sender/channel and verified From identity.
- Build the documented recipient/content structure for one controlled address and fixed test content.
- Persist an application send intent, submit once, and retain the available response/request correlation.
If using a maintained SMTP client instead, follow the service’s current relay host, port, authentication, and TLS instructions. API and relay connection details are not interchangeable just because both submit mail.
Inspect application status and delivery
SMTP.com’s API documentation specifies a JSend response model. Check its application status/data/error information as well as HTTP status; parsing JSON is not evidence that a message was accepted.
Inspect the relevant provider activity and controlled recipient. A submission acknowledgement is not final inbox placement. A timeout after submission can be ambiguous, so investigate before replaying the operation or failing over to another provider.
Use reporting/feedback to establish per-recipient outcomes in production. MailKite has its own sending SDK and domain verification, and does not accept SMTP.com channel IDs or API keys.