EHLO 의 응답으로 250-AUTH LOGIN 이 나오면 인증가능
client -> AUTH LOGIN // 시작을 알림
server -> 334 VXNlcm5hbWU6 // Username: 의 BASE64표기
client -> cGp3MDAwMjc= // ID 를 BASE64 로 보냄
server -> 334 UGFzc3dvcmQ6 // Password: 의 BASE64표기
client -> cGp3MDAwMjc= // PW 를 BASE64 로 보냄
server -> 235 ok, go ahead (#2.0.0) // 성공!
server -> 535 authorization failed (#5.7.0) // 오류!
<<< 220 smtp4.mail.krn.yahoo.com ESMTP
>>> EHLO TGNT04
<<< 250-smtp4.mail.krn.yahoo.com
250-AUTH LOGIN PLAIN XYMCOOKIE
250-PIPELINING
250 8BITMIME
>>> AUTH LOGIN
<<< 334 VXNlcm5hbWU6
>>> cGp3MDAwMjc=
<<< 334 UGFzc3dvcmQ6
>>> YWRvcHBp
<<< 235 ok, go ahead (#2.0.0)
>>> MAIL FROM: <pjw00027@yahoo.co.kr>
<<< 250 ok
>>> RCPT TO: <pjw@toolgen.com>
<<< 250 ok
>>> DATA
<<< 354 go ahead
>>> Message-ID: <001201c5b2e9$67aafb70$bd349edd@TGNT04>
From: =?ks_c_5601-1987?B?udrB+L/s?= <pjw00027@yahoo.co.kr>
To: <pjw@toolgen.com>
Subject: t1
...
------=_NextPart_000_000F_01C5B334.D6813370--
.
<<< 250 ok 1126014399 qp 5511
>>> QUIT
<<< 221 smtp4.mail.krn.yahoo.com