Simple definition
The mechanism by which a client authenticates to a server SMTP before sending messages.
Technical definition
SMTP Authentication adds authentication methods to SMTP and is generally used on a submission service rather than on server-to-server transport.
What is it used for ?
Prevent unauthorized use of a server as a send relay.
Practical example
An application WordPress may be authenticated with the SMTP its supplier with an authorized account.
Common issues
- Authentication SMTP deactivated
- Incorrect identifiers
- Unauthorised From address for account
Related terms
Key takeaway: This entry explains the general operation of the term. Exact settings may vary depending on software, vendors and environments.
See also: SMTP 535 5.7.3.