SMTP

SMTP (Simple Mail Transfer Protocol) is a {{glossary("protocol")}} used to send a new email. Like {{glossary("POP")}} and {{glossary("NNTP")}}, it is a {{Glossary("state machine")}}-driven protocol.

The protocol is relatively straightforward. Primary complications include supporting various authentication mechanisms (GSSAPI, CRAM-MD5, NTLM, MSN, AUTH LOGIN, AUTH PLAIN, etc.), handling error responses, and falling back when authentication mechanisms fail (e.g., the server claims to support a mechanism, but doesn't).

See also

• SMTP (Wikipedia)
• Related glossary terms:
  • {{glossary("NNTP")}}
  • {{glossary("POP")}}
  • {{glossary("protocol")}}
  • {{Glossary("state machine")}}