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。

youdao

All electronic mail is transferred using a mail transfer agent (MTA), and Sendmail is the most popular MTA, so this warning affected many organizations worldwide.

所有的电子邮件都通过邮件传输代理(mail transfer agent, MTA)来传输，Sendmail则是最流行的MTA，所以这个警告影响了世界范围内的很多组织。

youdao

The mail transfer agent is also known as the mail server and is simply software that sends E-mail from one computer to another.

邮件传输代理也叫邮件服务器，是用来把邮件从一台计算机发送到另一台计算机的软件。

youdao

Ozancin wagged his finger at the sendmail mail transfer agent (MTA) as the cause of many past security exploits, including but not limited to buffer overflows.

CNN: Analysis: Linux security