SMTP（Simple Mail Transfer Protocol)和POP3（Post Office Protocol 3)有什么区别?重点是区别

SMTP（Simple Mail Transfer Protocol)和POP3（Post Office Protocol 3)有什么区别?重点是区别 英语翻译Simple Mail Transfer Protocol (SMTP),The method by which Internet mail is delivered from one computer to another.SMEs,small to medium sized companies and enterprises.S-Mime Encryption,Protects the privacy of email.If the sender and receiv ####@163.com SMTP error,RCPT TO:550 Invalid User还有一个问题:#####@163.com SMTP error,DOT:550 Requested action not taken:mail aEBwBsRYx0OP_foF.9702S2 is rejected,mx6,FNG请赐教 这篇英文说的是什么含义呢?SMTP error from remote mail server after end of data:host mx.126.split.netease.com [220.181.15.131]:550 Requested action not taken:mail wKjJHxeAlAToI01Ez3pvAA==.31795S2 is rejected,mx1 TRA是什么意思? simple Simple simple simple mail 这几行英语说的是什么含义?This message is generated by COREMAIL email system.I'm sorry to have to inform you that the message returnedhanzhixiu@21cn.com SMTP error,DOT:553 Mail data refused by AISP,rule [6535799]. 英语翻译This is the mail system at host smtp.sinamail.sina.com.cn.I'm sorry to have to inform you that your message could notbe delivered to one or more recipients.It's attached below.For further assistance,please send mail to postmaster.If you d 这两封信件里面的英文说的是什么意思?信件一：SMTP error from remote mail server after end of data:host mx.126.split.netease.com [220.181.15.135]:550 Requested action not taken:mail wKjJIyRAB0et+GxESlgZBw==.5253S2 is rejected,mx5信 线性代数中trA是什么意思 i tra to 线性代数中trA是什么意思~~ 这啥越南语啥意思啊em viet thu cho anh,sao khong thay anh tra loi em vay!ma anh co mail yahoo!messenger khong?neu ma anh co thi em voi anh chat noi chuyen ,con co the thay duoc nhau tren mang,anh co mail yahoo!messenger thi gui mail qua cho e SMTP error,RCPT TO:554 :Relay access