Updated method names to more accurately reflect their authentication mechanisms (SCRAM-SHA-1, SCRAM-SHA-1-PLUS, SCRAM-SHA-256, SCRAM-SHA-256-PLUS). Revised corresponding comments to improve clarity and maintain consistency.
Introduced additional SMTP authentication mechanisms: SCRAM-SHA-1, SCRAM-SHA-1-PLUS, SCRAM-SHA-256, and SCRAM-SHA-256-PLUS. Added corresponding error messages for unsupported authentication types. This enhances security options for SMTP connections.