linux 里如何telnet一个要求ssl的pop3 邮箱

telnet 一个不需要ssl的pop邮箱。

这个比较简单了，如下的操作就可以查看你的邮箱里的邮件。（具体命令可以查看pop3 的命令）

[root@localhost ~]# telnet system.mail 110
Trying 10.100.3.228...
Connected to system.mail (10.100.3.228).
Escape character is '^]'.
+OK lenovo.mail POP MDaemon 8.0.2 ready
user test030000
+OK test030000... User ok
pass 1
+OK [e-mail]'s mailbox has 6 total messages (27678 octets)
list
+OK 6 27678
1 18671
2 1730
3 1742
4 1733
5 1899
6 1903
.
quit
+OK [e-mail] lenovo.mail POP Server signing off (6 messages left)
Connection closed by foreign host.

但是如果要telnet 一个pop3邮箱需要ssl的话，用telnet的话，是不能正常通讯的。

从google上搜索到了一个很好用的工具。

因为gmail需要ssl的，（例如你在设置outlook，foxmail的时候需要将ssl的那个选项悬赏）

如下：

openssl s_client -connect pop.gmail.com:995

用openssl的命令，就可以访问需要ssl的pop3 邮箱，非常方便。

[root@localhost ~]# openssl s_client -connect pop.gmail.com:995
CONNECTED(00000003)
depth=2 /C=US/O=Equifax/OU=Equifax Secure Certificate Authority
verify return:1
depth=1 /C=US/O=Google Inc/CN=Google Internet Authority
verify return:1
depth=0 /C=US/ST=California/L=Mountain View/O=Google Inc/CN=pop.gmail.com
verify return:1
---
Certificate chain
 0 s:/C=US/ST=California/L=Mountain View/O=Google Inc/CN=pop.gmail.com
  i:/C=US/O=Google Inc/CN=Google Internet Authority
 1 s:/C=US/O=Google Inc/CN=Google Internet Authority
  i:/C=US/O=Equifax/OU=Equifax Secure Certificate Authority
---
Server certificate
-----BEGIN CERTIFICATE-----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==
-----END CERTIFICATE-----
subject=/C=US/ST=California/L=Mountain View/O=Google Inc/CN=pop.gmail.com
issuer=/C=US/O=Google Inc/CN=Google Internet Authority
---
No client certificate CA names sent
---
SSL handshake has read 1703 bytes and written 300 bytes
---
New, TLSv1/SSLv3, Cipher is RC4-MD5
Server public key is 1024 bit
Compression: NONE
Expansion: NONE
SSL-Session:
  Protocol : TLSv1
  Cipher : RC4-MD5
  Session-ID: B6A78FD9089FC9EB2C9C58C853E5ACBAFBDDAB966E6436E6C95F184436F1CC27
  Session-ID-ctx: 
  Master-Key: E80F37D3F4DBD4DE65C5DB60A9FC3718AD12CFD09511B728ED495D10B3770288E470E52F700656C15D53B43D9873FB6F
  Key-Arg : None
  Krb5 Principal: None
  Start Time: 1256365429
  Timeout : 300 (sec)
  Verify return code: 0 (ok)
---
+OK Gpop ready for requests from 222.128.6.185 27pf13504606pzk.39
user username
+OK send PASS
pass password
+OK Welcome.
list
+OK 8 messages (43869 bytes)
1 3104
2 3412
3 9574
4 4529
5 7179
6 5366
7 4443
8 6262
.
quit
+OK Farewell.
read:errno=0