Prepare an SMTP.com sender and v4 API credential
Configure the correct SMTP.com sending context and secure API authentication without placing secrets in URLs.
Reviewed
SMTP.com provides managed relay and a v4 API. Before connecting a client, establish the provisioned sender/channel context and account/domain requirements with its dashboard and current documentation.
Configure the application connection
- Authenticate the intended sending domain using the service’s supplied DNS records.
- Select the sender/channel configuration used by this application and environment.
- Create the necessary API credential, or obtain the separately documented SMTP connection details if using relay.
- Store secrets only in backend configuration and keep account operations separate from ordinary message submission.
The API documentation describes v4 JSON requests and several API-key authentication methods. Prefer supported header-based authentication; do not put keys in URLs, query strings, browser history, or public logs merely because the API permits it.
Verify account and sender scope
Run one approved single-recipient test and check activity for the intended sender/channel. A credential accepted by an account resource does not prove the sender is authorized for every domain.
For onboarding, limit, authentication, or sender failures, fix that boundary rather than weakening controls. Outbound domain authentication does not migrate employee mailbox MX or provide reply receiving.
If MailKite receives application replies, configure a separate verified destination and document which service owns sending, receiving, and suppression state.