c语言 发送电子邮件

源码如下， 详情请参考windows网络编程，base64编码，RFC821文档的MIME格式说明，qq的MIME格式请从qq邮箱任意邮件导出eml文件。 以下源码在VC++6.0下编译通过，请在工程->设置->连接->对象库/模块中加入ws2_32.lib  测试用邮箱为172171882@qq.com，用于名密码已被修改，编译时请用自己的邮箱 要注意，MIME格式要求严格，tab，换行一个都不能少。 #include <stdio.h> #include <winsock2.h> #pragma comment(lib, "ws2_32.lib") //Global Variables Declaration const char* HostName = "Smtp.qq.com"; //Mail Server const char* MailData = "From: \"zhao\"<172171882@qq.com>\r\n" "To: \"zhao\"<172171882@qq.com>\r\n" "Date: Mon, 25 Oct 2005 14:24:27 +0800\r\n" "Subject: picture is comming!\r\n\r\n" "new hello!\r\n.\r\n"; //User-Define Function Declaration void Usage(void);                       //CopyRight const char base[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";  char *base64_encode(char* data, int data_len) { //int data_len = strlen(data); int prepare; int ret_len; int temp = 0; char *ret = NULL; char *f = NULL; int tmp = 0; char changed[4]; int i = 0; ret_len = data_len / 3; temp = data_len % 3; if (temp > 0) { ret_len += 1; } ret = (char *)malloc(ret_len*4 + 1); if ( ret == NULL) { printf("No enough memory.\n"); exit(0); } f = ret; while (tmp < data_len) { temp = 0; prepare = 0; memset(changed, '\0', 4); while (temp < 3) { //printf("tmp = %d/n", tmp); if (tmp >= data_len) { break; } prepare = ((prepare << 8) | (data[tmp] & 0xFF)); tmp++; temp++; } prepare = (prepare<<((3-temp)*8)); //printf("before for : temp = %d, prepare = %d/n", temp, prepare); for (i = 0; i < 4 ;i++ ) { if (temp < i) { changed[i] = 0x40; } else { changed[i] = (prepare>>((3-i)*6)) & 0x3F; } *f = base[changed[i]]; //printf("%.2X", changed[i]); f++; } } *f = '\0'; return ret; } void SendMsg(SOCKET server, const char *msg) {     char Buffer[1024] = {0};     int ret = 0; //Send "HELO Server\r\n" to Mail Server     ret = send(server, msg, strlen(msg), 0);     if (ret == SOCKET_ERROR)     { printf("Send %s to Mail Failure...\n", msg); goto CleanUP;     }     else     { printf("%s OK\n", msg);        }           //Recv Data From Mail Server     ZeroMemory(Buffer, sizeof(Buffer));     ret = recv(server, Buffer, sizeof(Buffer), 0);     if (ret == SOCKET_ERROR)     { printf("Receive Data From Mail Server Failure...\n");     goto CleanUP;          }     else     { Buffer[ret] = ' '; printf("%s\n", Buffer);     } return ; CleanUP: if (server != INVALID_SOCKET) { closesocket(server);   //Close Socket Handle } WSACleanup();                     //Cleanup Winsock     exit(0); } //Mail Function int SendMain(int argc, char *argv[]) {     WSADATA wsa;     struct hostent *pHostent = NULL;     SOCKET server = INVALID_SOCKET;     struct sockaddr_in ServerAddr;     int ret = 0;     char Buffer[1024] = {0}; char *minedata;          Usage();                                         //Print Copyright          if (WSAStartup(MAKEWORD(2, 2), &wsa) != 0)       //Init Socket     { printf("Init Socket Failure...\n"); if (server != INVALID_SOCKET) { closesocket(server);   //Close Socket Handle } WSACleanup();   exit(0);     }          server = socket(AF_INET, SOCK_STREAM, 0);        //Create Socket Handle     if (server == INVALID_SOCKET)     { printf("Create Socket Failure...\n"); if (server != INVALID_SOCKET) { closesocket(server);   //Close Socket Handle } WSACleanup();   exit(0);     }          pHostent = gethostbyname(HostName);              //Get Mail Server Name     if (pHostent == NULL)     { printf("The Host Name is Invalid...\n"); if (server != INVALID_SOCKET) { closesocket(server);   //Close Socket Handle } WSACleanup();   exit(0);     }          //Fill Sockaddr_in Structure     ServerAddr.sin_family = AF_INET;     memcpy(&ServerAddr.sin_addr.S_un.S_addr, pHostent->h_addr_list[0], pHostent->h_length);     ServerAddr.sin_port = htons(25);          //Connect to remote Mail Server     ret = connect(server, (struct sockaddr*)&ServerAddr, sizeof(ServerAddr));     if (ret == SOCKET_ERROR)     { printf("Connect Mail Server Failed...\n"); if (server != INVALID_SOCKET) { closesocket(server);   //Close Socket Handle } WSACleanup();   exit(0);     }          printf("Connect to %s...\n", inet_ntoa(ServerAddr.sin_addr));          //Recv Data From Mail Server     ZeroMemory(Buffer, sizeof(Buffer));     ret = recv(server, Buffer, sizeof(Buffer), 0);     if (ret == SOCKET_ERROR)     { printf("Receive Data From Mail Server Failure...\n");     if (server != INVALID_SOCKET) { closesocket(server);   //Close Socket Handle } WSACleanup();   exit(0);         }     else     { Buffer[ret] = ' '; printf("%s\n", Buffer);     }          SendMsg(server, "HELO Server\r\n");     SendMsg(server, "AUTH LOGIN\r\n");     SendMsg(server, "MTcyMTcxOdfDgy\r\n");//用户名     SendMsg(server, "MTM2OTc2NzMsdfwNjU=\r\n");//密码     SendMsg(server, "MAIL FROM: <172171882@qq.com>\r\n");     SendMsg(server, "RCPT TO: <172171882@qq.com>\r\n");     SendMsg(server, "Data\r\n"); ////////////////////////////////////////////////////////////////////////////////////////     FILE* pf = fopen("d:\\pic.jpg","rb");     fseek(pf,0,SEEK_END);       int filelen = ftell(pf);       fseek(pf,0,SEEK_SET);       char* filebuf = (char*) malloc(filelen);       fread(filebuf,1,filelen,pf);       char* filebase64 = base64_encode(filebuf,filelen);  minedata = (char *)malloc(strlen(filebase64)+4096); ZeroMemory(minedata, strlen(filebase64)+4096); sprintf(minedata, "X-QQ-SSF: 0001000000000020000000000000000\r\n" "X-HAS-ATTACH: no\r\n" "X-QQ-BUSINESS-ORIGIN: 2\r\n" "X-Originating-IP: 210.45.11.132\r\n" "X-QQ-STYLE: \r\n" "X-QQ-mid: webmail221t1333761329t3697219\r\n" "From: \"=?gbk?B?srvKtr79?=\" <172171882@qq.com>\r\n" "To: \"=?gbk?B?ztLX1Ly6tcTTys/k?=\" <172171882@qq.com>\r\n" "Subject: =?gbk?B?zbzGrA==?=\r\n" "Mime-Version: 1.0\r\n" "Content-Type: multipart/mixed;\r\n" "\tboundary=\"----=_NextPart_4F7F9531_08B02E20_6E086CD1\"\r\n" "Content-Transfer-Encoding: 8Bit\r\n" "Date: Sat, 7 Apr 2012 09:15:29 +0800\r\n" "X-Priority: 3\r\n" "Message-ID: <tencent_1BEFD3F31DA22E5629F9C688@qq.com>\r\n" "X-QQ-MIME: TCMime 1.0 by Tencent\r\n" "X-Mailer: QQMail 2.x\r\n" "X-QQ-Mailer: QQMail 2.x\r\n\r\n" "This is a multi-part message in MIME format.\r\n\r\n" "------=_NextPart_4F7F9531_08B02E20_6E086CD1\r\n" "Content-Type: multipart/alternative;\r\n" "\tboundary=\"----=_NextPart_4F7F9531_08B02E20_212FB248\";\r\n\r\n" "------=_NextPart_4F7F9531_08B02E20_212FB248\r\n" "Content-Type: text/plain;\r\n" "\tcharset=\"gbk\"\r\n" "Content-Transfer-Encoding: base64\r\n\r\n\r\n\r\n" "------=_NextPart_4F7F9531_08B02E20_212FB248\r\n" "Content-Type: text/html;\r\n" "\tcharset=\"gbk\"\r\n" "Content-Transfer-Encoding: base64\r\n\r\n" "PGRpdj48YnI+PC9kaXY+\r\n\r\n" "------=_NextPart_4F7F9531_08B02E20_212FB248--\r\n\r\n" "------=_NextPart_4F7F9531_08B02E20_6E086CD1\r\n" "Content-Type: application/octet-stream;\r\n" "\t charset=\"gbk\";\r\n" "name=\"pic.jpg\"\r\n" "Content-Disposition: attachment; filename=\"pic.jpg\"\r\n" "Content-Transfer-Encoding: base64\r\n\r\n" "%s\r\n\r\n" "------=_NextPart_4F7F9531_08B02E20_6E086CD1--\r\n\r\n" "\r\n.\r\n", filebase64 );      SendMsg(server, minedata);     SendMsg(server, "QUIT\r\n"); if (server != INVALID_SOCKET) { closesocket(server);   //Close Socket Handle } WSACleanup();                     //Cleanup Winsock           return 0; } //End of Mail Function //Usage Function Defination, Provider Some help to User void Usage(void) { printf("------------------------------------------------------------\n"); printf("The Demo of Collects data by Sending mail\n"); printf("Codz by Netxfly [E.S.T]\n"); printf("------------------------------------------------------------\n"); return; }