The mail transfer agent receives the messages from another mail transfer agent, a mail user agent, or a mail submission agent.

邮件传输代理从另一个邮件传输代理、邮件用户代理或邮件提交代理处接收消息。

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For example, if you're packaging a mail user agent or mail transport agent, there are some specific considerations that apply.

例如，如果您正在对一个邮件用户代理程序或邮件传输代理程序进行打包，那么有些特定的考虑事项适用于这种情形。

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The Out of Office agent automatically determines the home mail server of the user, and enables the agent to run on that server. (See the sidebar.)

离开办公室代理自动指定用户的主邮件服务器，并启用要运行在该服务器上的代理(参见侧栏)。

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