从终端连接 Gmail SMTP 服务器

建立连接后服务器返回消息:

Resolving 'smtp.gmail.com'...
Connecting to '173.194.79.108:465'...
- Certificate type: X.509
- Got a certificate list of 2 certificates.
- Certificate[0] info:
- subject `C=US,ST=California,L=Mountain View,O=Google Inc,CN=smtp.gmail.com', issuer `C=US,O=Google Inc,CN=Google Internet Authority', RSA key 1024 bits, signed using RSA-SHA1, activated `2011-11-18 01:57:17 UTC', expires `2012-11-18 02:07:17 UTC', SHA-1 fingerprint `f392aeb428fe64036fe155ed719e5ff688905a57'
- Certificate[1] info:
- subject `C=US,O=Google Inc,CN=Google Internet Authority', issuer `C=US,O=Equifax,OU=Equifax Secure Certificate Authority', RSA key 1024 bits, signed using RSA-SHA1, activated `2009-06-08 20:43:27 UTC', expires `2013-06-07 19:43:27 UTC', SHA-1 fingerprint `dd7a7f131ddba33d3e8670179483e6fea6987d6a'
- The hostname in the certificate matches 'smtp.gmail.com'.
- Peer's certificate issuer is unknown
- Peer's certificate is NOT trusted
- Version: TLS1.2
- Key Exchange: RSA
- Cipher: ARCFOUR-128
- MAC: SHA1
- Compression: NULL
- Handshake was completed

- Simple Client Mode:

220 mx.google.com ESMTP sr4sm8864139pbc.24

接着输入

ehlo

返回

250-mx.google.com at your service
250-SIZE 35882577
250-8BITMIME
250-AUTH LOGIN PLAIN XOAUTH
250 ENHANCEDSTATUSCODES

连接成功，接下来输入用户名、密码即可登录。