C語言發送郵件 完整代碼：
#include?<windows.h>#include?<stdio.h>
#include?<WinSock.h>
#include?<iostream>
using?namespace?std;
#pragma?comment(lib,?"ws2_32.lib")
struct?Base64Date6
{
unsigned?int?d4:6;
unsigned?int?d3:6;
unsigned?int?d2:6;
unsigned?int?d1:6;
};
//?協議中加密部分使用的是base64方法
char?ConvertToBase64?(charc6);
void?EncodeBase64?(char*dbuf,?char?*buf128,?int?len);
void?SendMail?(char*email,char?*body);
int?OpenSocket(struct?sockaddr?*addr);
int?main()
{
char?EmailTo[]?=?"xushiladeng@qq.com";
char?EmailContents[]=?"From:?\"lucy\"<xushiladeng@qq.com>\r\n"
"To:?\"dasiy\"<xushiladeng@qq.com>\r\n"
"Subject:?Hello\r\n\r\n"
"Hello?World,?Hello?Email!"
//"DATA\r\n"?//告訴服務器下面是郵件
//下面是郵件頭
"TO:?xushiladeng@qq.com\r\n"
"FROM:?xushiladeng@qq.com\r\n"
"SUBJECT:?SMTP協議測試\r\n"
"Date:2015-04-20\r\n"
"X-Mailer:fice's?mailer\r\n"
"MIMI-Version:1.0\r\n"
"Content-Type:multipart/mixed;boundary=\"#BOUNDARY#\"\r\n\r\n"//設置邊界值，區分郵件內容的?兩個回車換行
"Content-Transfer-Encoding:7bit\r\n\r\n"
"This?is?a?multi-part?message?in?MIME?format\r\n\r\n"
//發送郵件內容頭部信息
"--#BOUNDARY#\r\n"
"Content-Type:?text/plain;charset=gb2312\r\n"
"Content-Transfer-Encoding:printable\r\n\r\n"
//發送郵件的內容部分
"SMTP協議測試：發送附件/n----by?fice?2015.04.20\r\n"
//發送附件頭部信息
"--#BOUNDARY#\r\n"
"Content-Type:text/plain;name=student.txt\r\n"
"Content-Transfer-Encoding:base64\r\n"
"Content-Disposition:attachment;filename=\"test.txt\"\r\n\r\n";
SendMail(EmailTo,?EmailContents);
return?0;
}
char?ConvertToBase64(char?uc)
{
if(uc?<?26)
{
return?'A'?+?uc;
}
if(uc?<?52)
{
return?'a'?+?(uc?-?26);
}
if(uc?<?62)
{
return?'0'?+?(uc?-?52);
}
if(uc?==?62)
{
return?'+';
}
return?'/';
}
//?base64的實現
void?EncodeBase64(char?*dbuf,?char?*buf128,?int?len)
{
struct?Base64Date6?*ddd?=?NULL;
inti=?0;
char?buf[256]?=?{0};
char?*tmp?=?NULL;
char?cc=?'\0';
memset(buf,?0,?256);
strcpy_s(buf,?256,?buf128);
for(i?=?1;?i?<=?len/3;?i++)
{
tmp?=?buf?+?(i-1)*3;
cc?=?tmp[2];
tmp[2]?=?tmp[0];
tmp[0]?=?cc;
ddd?=?(struct?Base64Date6?*)tmp;
dbuf[(i-1)*4+0]?=?ConvertToBase64((unsigned?int)ddd->d1);
dbuf[(i-1)*4+1]?=?ConvertToBase64((unsigned?int)ddd->d2);
dbuf[(i-1)*4+2]?=?ConvertToBase64((unsigned?int)ddd->d3);
dbuf[(i-1)*4+3]?=?ConvertToBase64((unsigned?int)ddd->d4);
}
if(len?%?3?==?1)
{
tmp?=?buf?+?(i-1)*3;
cc?=?tmp[2];
tmp[2]?=?tmp[0];
tmp[0]?=?cc;
ddd?=?(struct?Base64Date6?*)tmp;
dbuf[(i-1)*4+0]?=?ConvertToBase64((unsigned?int)ddd->d1);
dbuf[(i-1)*4+1]?=?ConvertToBase64((unsigned?int)ddd->d2);
dbuf[(i-1)*4+2]?=?'=';
dbuf[(i-1)*4+3]?=?'=';
}
if(len%3?==?2)
{
tmp?=?buf+(i-1)*3;
cc?=?tmp[2];
tmp[2]?=?tmp[0];
tmp[0]?=?cc;
ddd?=?(struct?Base64Date6?*)tmp;
dbuf[(i-1)*4+0]?=?ConvertToBase64((unsigned?int)ddd->d1);
dbuf[(i-1)*4+1]?=?ConvertToBase64((unsigned?int)ddd->d2);
dbuf[(i-1)*4+2]?=?ConvertToBase64((unsigned?int)ddd->d3);
dbuf[(i-1)*4+3]?=?'=';
}
return;
}
//?發送郵件
void?SendMail(char?*email,?char?*body)
{
int?sockfd?=?{0};
charbuf[1500]?=?{0};
charrbuf[1500]?=?{0};
charlogin[128]?=?{0};
charpass[128]?=?{0};
WSADATA?WSAData;
struct?sockaddr_in?their_addr?=?{0};
WSAStartup(MAKEWORD(2,?2),?&WSAData);
memset(&their_addr,?0,?sizeof(their_addr));
their_addr.sin_family?=?AF_INET;
their_addr.sin_port=?htons(25);
hostent*?hptr?=?gethostbyname("smtp.126.com");?
memcpy(&their_addr.sin_addr.S_un.S_addr,?hptr->h_addr_list[0],?hptr->h_length);?
printf("IP?of?smpt.126.com?is?:?%d:%d:%d:%d\n",?
their_addr.sin_addr.S_un.S_un_b.s_b1,?
their_addr.sin_addr.S_un.S_un_b.s_b2,?
their_addr.sin_addr.S_un.S_un_b.s_b3,?
their_addr.sin_addr.S_un.S_un_b.s_b4);?
//?連接郵件服務器，如果連接後沒有響應，則2?秒後重新連接
sockfd?=?OpenSocket((struct?sockaddr?*)&their_addr);
memset(rbuf,?0,?1500);
while(recv(sockfd,?rbuf,?1500,?0)?==?0)
{
cout<<"reconnect..."<<endl;
Sleep(2);
sockfd?=?OpenSocket((struct?sockaddr?*)&their_addr);
memset(rbuf,?0,?1500);
}
cout<<rbuf<<endl;
//?EHLO
memset(buf,?0,?1500);
sprintf_s(buf,?1500,?"EHLO?HYL-PC\r\n");
send(sockfd,?buf,?strlen(buf),?0);
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"EHLO?REceive:?"<<rbuf<<endl;
//?AUTH?LOGIN
memset(buf,?0,?1500);
sprintf_s(buf,?1500,?"AUTH?LOGIN\r\n");
send(sockfd,?buf,?strlen(buf),?0);
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"Auth?Login?Receive:?"<<rbuf<<endl;
//?USER
memset(buf,?0,?1500);
sprintf_s(buf,?1500,?"xushiladeng@qq.com");//妳的郵箱賬號
memset(login,?0,?128);
EncodeBase64(login,?buf,?strlen(buf));
sprintf_s(buf,?1500,?"%s\r\n",?login);
send(sockfd,?buf,?strlen(buf),?0);
cout<<"Base64?UserName:?"<<buf<<endl;
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"User?Login?Receive:?"<<rbuf<<endl;
//?PASSWORD
sprintf_s(buf,?1500,?"********");//妳的郵箱密碼
memset(pass,?0,?128);
EncodeBase64(pass,?buf,?strlen(buf));
sprintf_s(buf,?1500,?"%s\r\n",?pass);
send(sockfd,?buf,?strlen(buf),?0);
cout<<"Base64?Password:?"<<buf<<endl;
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"Send?Password?Receive:?"<<rbuf<<endl;
//?MAIL?FROM
memset(buf,?0,?1500);
sprintf_s(buf,?1500,?"MAIL?FROM:?<xushiladeng@qq.com>\r\n");
send(sockfd,?buf,?strlen(buf),?0);
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"set?Mail?From?Receive:?"<<rbuf<<endl;
//?RCPT?TO?第壹個收件人
sprintf_s(buf,?1500,?"RCPT?TO:<%s>\r\n",?email);
send(sockfd,?buf,?strlen(buf),?0);
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"Tell?Sendto?Receive:?"<<rbuf<<endl;
//?DATA?準備開始發送郵件內容
sprintf_s(buf,?1500,?"DATA\r\n");
send(sockfd,?buf,?strlen(buf),?0);
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"Send?Mail?Prepare?Receive:?"<<rbuf<<endl;
//?發送郵件內容，\r\n.\r\n內容結束標記
sprintf_s(buf,?1500,?"%s\r\n.\r\n",?body);
send(sockfd,?buf,?strlen(buf),?0);//發送郵件，不帶附件的內容
//用二進制方式讀取附件文件內容並轉為base64格式?
FILE*?pf?=?fopen("D:\\test.txt","rb");
fseek(pf,0,SEEK_END);
int?filelen?=?ftell(pf);
char*?filebuf?=?(char*)?malloc(filelen);
char*?filebase64?=?(char*)?malloc(filelen*2);
memset(filebase64,0,filelen*2);
fseek(pf,0,SEEK_SET);
fread(filebuf,1,filelen,pf);?
EncodeBase64(filebase64,filebuf,filelen);?
send(sockfd,?filebase64,?strlen(filebase64),?0);//發送郵件的內容
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"Send?Mail?Receive:?"<<rbuf<<endl;
//?QUIT
sprintf_s(buf,?1500,?"QUIT\r\n");
send(sockfd,?buf,?strlen(buf),?0);
memset(rbuf,?0,?1500);
recv(sockfd,?rbuf,?1500,?0);
cout<<"Quit?Receive:?"<<rbuf<<endl;
//清理工作
closesocket(sockfd);
WSACleanup();
return;
}
//?打開TCP?Socket連接
int?OpenSocket(struct?sockaddr?*addr)
{
int?sockfd?=?0;
sockfd=socket(PF_INET,?SOCK_STREAM,?0);
if(sockfd?<?0)
{
cout<<"Open?sockfd(TCP)?error!"<<endl;
exit(-1);
}
if(connect(sockfd,?addr,?sizeof(struct?sockaddr))?<?0)
{
cout<<"Connect?sockfd(TCP)?error!"<<endl;
exit(-1);
}
return?sockfd;
}