如何用汇编写邮件发送程序

小弟入门不久，最近在写一个东东，需要一个邮件发送程序，看了别人写的一些代码，自己‘抄’了一边，准备自己给自己发送一份邮件，调试时send成功返回，可并未受到邮件，大家看看是哪里写错了，先谢了。

.386
.model flat,stdcall
option casemap:none

include windows.inc
include kernel32.inc
includelib kernel32.lib
include user32.inc
includelib user32.lib
include wsock32.inc
includelib wsock32.lib


.const
szLocation db \'mail.sina.com.cn\', 0
Format db \'Begin connect: %s\', 0
Receiver db \'Jzz2004@sina.com\', 0
MsgSuccess db \'Success\', 0
_HostName  db \'Jzz2004\', 0

.data?
buffer1 db 20h dup (?)
buffer2 db 20h dup (?)
buffer3 db 100h dup (?)
buffer4 db 100h dup (?)
buffer db 100h dup (?)
hostname db 100h dup (?)





.code
start:
push offset buffer
push 101h
call WSAStartup
or eax, eax
jnz _Exit

invoke socket, AF_INET, SOCK_STREAM, 0
inc eax
or eax, eax
jz _WSACleanUp
dec eax
mov ebx, eax

mov word ptr [buffer], AF_INET
invoke htons, 25
mov word ptr [buffer + 2], ax

push offset szLocation
call gethostbyname
or eax, eax
jz _CloseSocket

mov esi, [eax + 0ch]
_EnumIPAddress:
cmp dword ptr [esi], 0
jz _CloseSocket
lodsd
mov eax, [eax]
mov dword ptr [buffer + 4], eax
invoke connect, ebx, offset buffer, sizeof sockaddr_in
or eax, eax
jnz _EnumIPAddress

push eax
push esp
push offset hostname
call GetComputerName
pop eax

call PushMailHeader
db \'HELO mail.sian.com.cn\', 0dh, 0ah
db \'MAIL FROM: Jzz2004@sina.com\', 0dh, 0ah
db \'RCPT TO: %s\', 0dh, 0ah
db \'DATA\', 0dh, 0ah
db \'FROM:%s@sina.com\', 0dh, 0ah
db \'TO: %s\', 0dh, 0ah
db \'SUBJECT: %s is comming!\', 0dh, 0ah, 0
PushMailHeader:
pop eax
push offset _HostName
push offset Receiver
push offset _HostName
push offset Receiver
push eax
push offset buffer4
call wsprintf

push 0
push eax
push offset buffer4
push ebx
call send
cmp eax, SOCKET_ERROR
jz _CloseSocket

invoke Sleep, 1000

call PushMailEnd
db 0dh, 0ah, \'.\', 0dh, 0ah
PushMailEnd:
pop eax
invoke send, ebx, eax, 5, 0
cmp eax, SOCKET_ERROR
jz _CloseSocket
invoke Sleep, 1000

call PushMailQuit
db \'QUIT\', 0dh, 0ah, 0
PushMailQuit:
pop eax
invoke send, ebx, eax, 6, 0
cmp eax, SOCKET_ERROR
jz _CloseSocket
invoke Sleep, 1000

_CloseSocket:
push ebx
call closesocket
_WSACleanUp:
call WSACleanup
_Exit:
invoke ExitProcess, 0
end start

又找了一些网站，在进行auth login时，我将Base64之后的username和password发送过去，回显总是535 auth failure；如果故意用错误的username和password，回显结果便是535 auth error,然后便遗失对主机的连接。
对比两种不同的错误信息（虽然错误代码一样的），我想auth login时是不是还要对Base64之后的username和password进行一些其他的处理呢？

还是不行，是不是某些服务器有特殊的命令？

试试把
szAuth db \'AUTH LOGIN\', 13, 10, 0
改成
szAuth db \'AUTH LOGIN \', 13, 10, 0

很久没用汇编语言写东西了 !!

谢谢楼上几位提供的资料，但还是有问题：

.data
socketaddress sockaddr_in <?>
szHelo db  \'HELO mail.sina.com.cn\',13, 10, 0
szAuth db  \'AUTH LOGIN\', 13, 10, 0


1)
connect, hSocket, offset socketaddress, sizeof sockaddr_in
recv的内容是：220 sina.com ESMTP
2)
lstrlen, offset szHelo
send,hSocket, offset szHelo, eax, 0
recv的内容是：250 sina.com
3)
lstrlen, offset szAuth
send, hSocket, offset szAuth, eax, 0
recv的内容是：553,....... -unrecognized authentiction type
4)
然后BufferToBase64后发送用户名和密码recv的内容都是 unimplemented

为什么发送‘AUTH LOGIN’失败, 是不是这个命令格式有问题?

用汇编语言写ESMTP邮件发送程序
http://www.luocong.com/articles/show_article.asp?Article_ID=21

base64 是用64个字母表示的编码。其编码表为：(0-63) A-Z,a-z,0-9,+,/ 。另等号作填充字符。每三个原码编码后变为四个字。不足则用=填。其规则为三个原码的24bits 化为四个6bits,再查表。
  
如：BOY---> 0x42 0x4F 0x59
---->0100 0010 0100 1111 0101 1001    
---->010000 100100 111101 011001
---->0x10   0x24   0x3D   0x19
---->QK9Z

找了一点资料，发现有些代码里涉及到了Base64, 具体内容好象是将Ansi转换成另一种形式。
Base64是什么呢？这和发邮件有什么关系啊？
晚辈实在看不明白，还望高手指点，谢谢。

实现smtp协议就可以了.不过服务器端认证方式有好几种.

看看pop协议吧

你先要\"AUTH LOGIN \",有些SMTP server要Login,username and password先用base64编码
给你一段C.

 

//HELO command session
//Used to identify the sender-SMTP to the receiver-SMTP
//The sender-SMTP establishes a two-way transmission channel to a receiver-SMTP
strcpy (Data2Srv, \"HELO \");
strcat (Data2Srv, srv.address);
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);


strcpy (Data2Srv, \"AUTH LOGIN \");
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);

ZeroMemory( Base64DataE,BUFFER_DEFAULT_SIZE);
strcpy (Base64PData, USERNAME);
b64encode( Base64PData, Base64DataE, strlen(USERNAME), 4 );

strcpy (Data2Srv, Base64DataE); // Username
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);


ZeroMemory( Base64DataE,BUFFER_DEFAULT_SIZE);
strcpy (Base64PData, UPASSWORD);
b64encode( Base64PData, Base64DataE, strlen(UPASSWORD), 4 );

strcpy (Data2Srv, Base64DataE); // Password
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);


strcpy (Data2Srv, \"MAIL FROM:<\");
strcat (Data2Srv, msg.FromAdd);
strcat (Data2Srv, \">\");
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);

//RCPT command session
//The SMTP-sender sends a RCPT command identifying a recipient of the mail.  
//If the SMTP-receiver can accept mail for that recipient it responds with an OK reply
strcpy (Data2Srv, \"RCPT TO:<\");
strcat (Data2Srv, msg.ToAdd);
strcat (Data2Srv, \">\");
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);

//DATA command session
//The SMTP-sender sends the mail data, terminating with a special sequence.  
//If the SMTP-receiver successfully processes the mail data it responds with an OK reply.
strcpy (Data2Srv, \"DATA \");
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);

strcpy (Data2Srv, \"SUBJECT: \");
strcat (Data2Srv, msg.Subject);
strcat (Data2Srv, CRLF);
strcat (Data2Srv, msg.MsgBody);
strcat (Data2Srv, CRLF);
strcat (Data2Srv, \".\");
strcat (Data2Srv, CRLF);
sendData (Data2Srv, ssmtp, FeedBack);
writeLog(logFile, FeedBack);