关于电子邮件发送方面的问题，急

Question

请问邮件服务器间是如何进行邮件收发的，有什么协议没？
还有就是有免smtp服务器的发送软件那是如何做到的

Answer 1

协议和服务器类型总是对应的,那自然就是POP3和SMTP协议http://www.codeguru.com/internet/index.shtml至于免Smtp服务器是因为本地计算机被当作Smtp服务器使用了!

Answer 2

其实pop3和smtp协议就是对服务器进行一些命令的执行。

Answer 3

Example
void TestHTMLMailWithGifWithAttach()
{
  // Create and initialize a message
  CMIMEMessage *pMsg= new CMIMEMessage; 
  pMsg->m_sFrom = FROM;
  pMsg->AddMultipleRecipients(MYSELF);
  pMsg->AddMultipleRecipients("[email protected]",
                              CMailMessage::BCC);
  pMsg->m_sSubject = "Test CMIMEmessage";
  // Create MIME containers
  CMIMEMessage::CMIMEPart *pMIMEmixed =
        pMsg->AddMIMEPart(CMIMEMessage::MIXED);
  CMIMEMessage::CMIMEPart *pMIMErelated =
        pMIMEmixed->AddMIMEPart(CMIMEMessage::RELATED);
  CMIMEMessage::CMIMEPart *pMIMEalternative = 
      pMIMErelated->AddMIMEPart(CMIMEMessage::ALTERNATIVE);
  // Alternative 1 : mail client does not support HTML...
  //      tell it in plain text 7Bits (warning : no 
  //      conversion is done)
  CString Text(
"Text that appear when client does not support HTML\r\n\r\n");
  pMIMEalternative->AddMIMEPart(CMIMEMessage::TEXT_PLAIN,Text);
  // Alternative 2 : mail client does support HTML...
  //      tell it in HTML text quoted-printable (warning : 
  //      no conversion is done)
  CString Html;
  Html=GetHTMLResource(IDR_HTML1);
  pMIMEalternative->AddMIMEPart(CMIMEMessage::TEXT_HTML,Html);
  // Prepare GIF image
  char* Gif;
  int Len;
  GetGIFResource(IDR_TOLLOGO, &Gif, &Len);
  // GIFS are related to HTML text : note 
  //    the string "IDR_TOLLOGO" which appears somewhere
  //    in IDR_HTML1 text
  pMIMErelated->AddMIMEPart(
         CMIMEMessage::APPLICATION_OCTETSTREAM_IMAGE,
         Gif,
         CMIMEMessage::MEMORY,
         "IDR_TOLLOGO",
         Len);
  GetGIFResource(IDR_HR, &Gif, &Len);
  pMIMErelated->AddMIMEPart(
         CMIMEMessage::APPLICATION_OCTETSTREAM_IMAGE,
         Gif,
         CMIMEMessage::MEMORY,
         "IDR_HR",
         Len);
  // Add attachment
  pMIMEmixed->AddMIMEPart(
         CMIMEMessage::APPLICATION_OCTETSTREAM,
         ATTACHMENT);
  // Do not forget to...
  pMsg->FormatMessage();
  // Then ...
  SendSMTP(pMsg);
}

Answer 4

基于 pop3 和 smtp 协议
比如可以用 telnet pop3.xxx 110
然后使用 pop3 命令操作。有 imail 服务软件能做邮件服务器。另外网上有很多 pop3 的代码，你去查一查吧。