求翻译：请输入您需要翻译的文本！发件人: "MAILER-DAEMON@messagelabs.com" 将发件人添加到联系人收件人: yangzhengwei2011@yahoo.com.cnThis is the mail delivery agent at messagelabs.com.是什么意思？

Please enter the text you need to translate! Sender: "MAILER-DAEMON@messagelabs.com" <mailer-daemon@messagelabs.com> to add the sender to contact recipients: yangzhengwei2011@yahoo.com.cnThis is the mail delivery agent at MessageLabs.com. </mailer-daemon@messagelabs.com>