效果图
main.cpp
1 #include <iostream>
2 #include "SendMail.h"
3 #include <string>
4 using namespace std;
5
6 int main()
7 {
8 char EmailContents[255]="From: \"名字\"<xxxxxxx@163.com>\r\nTo:";
9 char EmailTo[50];
10 char subject[50];
11 char content[50];
12 printf("要发送的邮箱账号：");
13 scanf("%s",EmailTo);
14 printf("你的标题：");
15 scanf("%s",subject);
16 printf("你的内容：");
17 scanf("%s",content);
18
19 strcat(EmailContents,EmailTo);
20 strcat(EmailContents,"\n");
21 strcat(EmailContents, "subject:");
22 strcat(EmailContents, subject);
23 strcat(EmailContents, "\r\n\r\n");
24 strcat(EmailContents, content);
25 strcat(EmailContents, "\r\n.\r\n\0");
26 SendMail(EmailTo, EmailContents);
27 return 0;
28 }
SendMail.cpp
1 #include "SendMail.h"
2
3 #pragma comment(lib, "ws2_32.lib")
4 #include <string.h>
5 struct Base64Date6
6 {
7 unsigned int d4 : 6;
8 unsigned int d3 : 6;
9 unsigned int d2 : 6;
10 unsigned int d1 : 6;
11 };
12
13 char ConvertToBase64(char uc)
14 {
15 if (uc < 26)
16 {
17 return 'A' + uc;
18 }
19 if (uc < 52)
20 {
21 return 'a' + (uc - 26);
22 }
23 if (uc < 62)
24 {
25 return '0' + (uc - 52);
26 }
27 if (uc == 62)
28 {
29 return '+';
30 }
31 return '/';
32 }
33
34 // base64的实现
35 void EncodeBase64(char *dbuf, char *buf128, int len)
36 {
37 struct Base64Date6 *ddd = NULL;
38 int i = 0;
39 char buf[256] = { 0 };
40 char *tmp = NULL;
41 char cc = '\0';
42
43 memset(buf, 0, 256);
44 strcpy(buf,buf128);
45 for (i = 1; i <= len / 3; i++)
46 {
47 tmp = buf + (i - 1) * 3;
48 cc = tmp[2];
49 tmp[2] = tmp[0];
50 tmp[0] = cc;
51 ddd = (struct Base64Date6 *)tmp;
52 dbuf[(i - 1) * 4 + 0] = ConvertToBase64((unsigned int)ddd->d1);
53 dbuf[(i - 1) * 4 + 1] = ConvertToBase64((unsigned int)ddd->d2);
54 dbuf[(i - 1) * 4 + 2] = ConvertToBase64((unsigned int)ddd->d3);
55 dbuf[(i - 1) * 4 + 3] = ConvertToBase64((unsigned int)ddd->d4);
56 }
57 if (len % 3 == 1)
58 {
59 tmp = buf + (i - 1) * 3;
60 cc = tmp[2];
61 tmp[2] = tmp[0];
62 tmp[0] = cc;
63 ddd = (struct Base64Date6 *)tmp;
64 dbuf[(i - 1) * 4 + 0] = ConvertToBase64((unsigned int)ddd->d1);
65 dbuf[(i - 1) * 4 + 1] = ConvertToBase64((unsigned int)ddd->d2);
66 dbuf[(i - 1) * 4 + 2] = '=';
67 dbuf[(i - 1) * 4 + 3] = '=';
68 }
69 if (len % 3 == 2)
70 {
71 tmp = buf + (i - 1) * 3;
72 cc = tmp[2];
73 tmp[2] = tmp[0];
74 tmp[0] = cc;
75 ddd = (struct Base64Date6 *)tmp;
76 dbuf[(i - 1) * 4 + 0] = ConvertToBase64((unsigned int)ddd->d1);
77 dbuf[(i - 1) * 4 + 1] = ConvertToBase64((unsigned int)ddd->d2);
78 dbuf[(i - 1) * 4 + 2] = ConvertToBase64((unsigned int)ddd->d3);
79 dbuf[(i - 1) * 4 + 3] = '=';
80 }
81 return;
82 }
83 // 发送邮件
84 void SendMail(char *email, const char *body)
85 {
86 int sockfd = { 0 };
87 char buf[1500] = { 0 };
88 char rbuf[1500] = { 0 };
89 char login[128] = { 0 };
90 char pass[128] = { 0 };
91 WSADATA WSAData;
92 struct sockaddr_in their_addr = { 0 };
93 WSAStartup(MAKEWORD(2, 2), &WSAData);
94 memset(&their_addr, 0, sizeof(their_addr));
95
96 their_addr.sin_family = AF_INET;
97 their_addr.sin_port = htons(25); // 一般是25端口不需要改
98 hostent* hptr = gethostbyname("smtp.163.com"); // 端口和服务器
99 memcpy(&their_addr.sin_addr.S_un.S_addr, hptr->h_addr_list[0], hptr->h_length);
100 printf("IP of smtp.163.com is : %d:%d:%d:%d\n",
101 their_addr.sin_addr.S_un.S_un_b.s_b1,
102 their_addr.sin_addr.S_un.S_un_b.s_b2,
103 their_addr.sin_addr.S_un.S_un_b.s_b3,
104 their_addr.sin_addr.S_un.S_un_b.s_b4);
105
106 // 连接邮件服务器，如果连接后没有响应，则2 秒后重新连接
107 sockfd = OpenSocket((struct sockaddr *)&their_addr);
108 memset(rbuf, 0, 1500);
109 while (recv(sockfd, rbuf, 1500, 0) == 0)
110 {
111 cout << "reconnect..." << endl;
112 Sleep(2);
113 sockfd = OpenSocket((struct sockaddr *)&their_addr);
114 memset(rbuf, 0, 1500);
115 }
116
117 cout << rbuf << endl;
118
119 // EHLO
120 memset(buf, 0, 1500);
121 sprintf(buf,"%s", "EHLO HYL-PC\r\n");
122 send(sockfd, buf, strlen(buf), 0);
123 memset(rbuf, 0, 1500);
124 recv(sockfd, rbuf, 1500, 0);
125 cout << "EHLO REceive: " << rbuf << endl;
126
127 // AUTH LOGIN
128 memset(buf, 0, 1500);
129 sprintf(buf, "%s", "AUTH LOGIN\r\n");
130 send(sockfd, buf, strlen(buf), 0);
131 memset(rbuf, 0, 1500);
132 recv(sockfd, rbuf, 1500, 0);
133 cout << "Auth Login Receive: " << rbuf << endl;
134
135 // USER
136 memset(buf, 0, 1500);
137 sprintf(buf,"%s", "xxxxxxx@163.com");//你的邮箱账号
138 memset(login, 0, 128);
139 EncodeBase64(login, buf, strlen(buf));
140 sprintf(buf,"%s\r\n", login);
141 send(sockfd, buf, strlen(buf), 0);
142 cout << "Base64 UserName: " << buf << endl;
143 memset(rbuf, 0, 1500);
144 recv(sockfd, rbuf, 1500, 0);
145 cout << "User Login Receive: " << rbuf << endl;
146
147 // PASSWORD
148 sprintf(buf,"%s", "xxxxxx");//你的邮箱密码
149 memset(pass, 0, 128);
150 EncodeBase64(pass, buf, strlen(buf));
151 sprintf(buf,"%s\r\n", pass);
152 send(sockfd, buf, strlen(buf), 0);
153 cout << "Base64 Password: " << buf << endl;
154
155 memset(rbuf, 0, 1500);
156 recv(sockfd, rbuf, 1500, 0);
157 cout << "Send Password Receive: " << rbuf << endl;
158
159 // MAIL FROM
160 memset(buf, 0, 1500);
161 sprintf(buf,"%s", "MAIL FROM: <xxxxxxxx@163.com>\r\n"); //此处要和发邮件的邮箱保持一致
162 send(sockfd, buf, strlen(buf), 0);
163 memset(rbuf, 0, 1500);
164 recv(sockfd, rbuf, 1500, 0);
165 cout << "set Mail From Receive: " << rbuf << endl;
166
167 // RCPT TO 第一个收件人
168 sprintf(buf, "RCPT TO:<%s>\r\n", email);
169 send(sockfd, buf, strlen(buf), 0);
170 memset(rbuf, 0, 1500);
171 recv(sockfd, rbuf, 1500, 0);
172 cout << "Tell Sendto Receive: " << rbuf << endl;
173
174 // DATA 准备开始发送邮件内容
175 sprintf(buf, "%s", "DATA\r\n");
176 send(sockfd, buf, strlen(buf), 0);
177 memset(rbuf, 0, 1500);
178 recv(sockfd, rbuf, 1500, 0);
179 cout << "Send Mail Prepare Receive: " << rbuf << endl;
180
181 // 发送邮件内容，\r\n.\r\n内容结束标记
182 sprintf(buf,"%s\r\n.\r\n", body);
183 send(sockfd, buf, strlen(buf), 0);
184 memset(rbuf, 0, 1500);
185 recv(sockfd, rbuf, 1500, 0);
186 cout << "Send Mail Receive: " << rbuf << endl;
187
188 // QUIT
189 sprintf(buf,"%s", "QUIT\r\n");
190 send(sockfd, buf, strlen(buf), 0);
191 memset(rbuf, 0, 1500);
192 recv(sockfd, rbuf, 1500, 0);
193 cout << "Quit Receive: " << rbuf << endl;
194
195 //清理工作
196 closesocket(sockfd);
197 WSACleanup();
198 return;
199 }
200 // 打开TCP Socket连接
201 int OpenSocket(struct sockaddr *addr)
202 {
203 int sockfd = 0;
204 sockfd = socket(PF_INET, SOCK_STREAM, 0);
205 if (sockfd < 0)
206 {
207 cout << "Open sockfd(TCP) error!" << endl;
208 exit(-1);
209 }
210 if (connect(sockfd, addr, sizeof(struct sockaddr)) < 0)
211 {
212 cout << "Connect sockfd(TCP) error!" << endl;
213 exit(-1);
214 }
215 return sockfd;
216 }
SendMail.h
1 #ifndef SENDMAIL_H_INCLUDED 2 #define SENDMAIL_H_INCLUDED 3 4 #include <windows.h> 5 #include <stdio.h> 6 #include <WinSock.h> 7 #include <iostream> 8 using namespace std; 9 10 // 协议中加密部分使用的是base64方法 11 char ConvertToBase64(char c6); 12 void EncodeBase64(char *dbuf, char *buf128, int len); 13 void SendMail(char *email, const char *body); 14 int OpenSocket(struct sockaddr *addr); 15 16 #endif // SENDMAIL_H_INCLUDED
来源：https://www.cnblogs.com/tangdingkang/p/12298383.html