人们常常把邮箱的帐号和密码在内网邮件服务器中做了设置，却没有相应在外网邮件服务器做设置。

Quite often people put their mailbox ID and password on the Incoming server Settings, but not on the Outgoing server Settings.

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另外在连接服务器(pop)时，传送的验证密码也是以明文形式传送的，同样容易引起密码的泄露，最终导致邮件被盗、泄密等。

Moreover, the password needed for authentication is also transmitted as plaintext when a connection to POP server is established, which may result in the stealing and divulging of the email.

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