golang 25端口发送邮件

>注 本例是基于**25**端口进行发送邮件。如果你的服务器为阿里云，阿里云是25号端口禁用的。TCP 25端口是默认的邮箱服务端口。基于安全考虑，云服务器ECS的25端口默认受限。建议您使用 **465** 端口发送邮件。 [阿里云相关文档页面](https://help.aliyun.com/knowledge_detail/40570.html?spm=5176.2020520165.120.d40570.79a27029prHGMc "阿里云相关文档页面")

>如果使用**ssl加密465端口**发送邮件。请参考参一篇文章 [golang 465 发送邮件](https://www.gwalker.cn/article-d4f042ag5a43275befd356c70e77dfa3.html "golang 443 发送邮件")

```go
package main

import (
   "fmt"
   "net/smtp"
   "strings"
)

//发送邮件的逻辑函数
func SendMail(user, password, host, to, subject, body, mailtype string) error {
   hp := strings.Split(host, ":")
   auth := smtp.PlainAuth("", user, password, hp[0])
   var content_type string
   if mailtype == "html" {
      content_type = "Content-Type: text/" + mailtype + "; charset=UTF-8"
   } else {
      content_type = "Content-Type: text/plain" + "; charset=UTF-8"
   }

msg := []byte("To: " + to + "\r\nFrom: " + user + "<" + user + ">\r\nSubject: " + subject + "\r\n" + content_type + "\r\n\r\n" + body)
   send_to := strings.Split(to, ";")
   err := smtp.SendMail(host, auth, user, send_to, msg)
   return err
}

func main() {
   // 邮箱账号
   user := "xxxxx@126.com"
   // 邮箱密码
   password := "xxx"
   //smtp地址及端口
   host := "smtp.126.com:25"
   //接收者，内容可重复，邮箱之间用；隔开
   to := "xxxxx@qq.com;xxxxx@126.com"
   //邮件主题
   subject := "测试通过golang发送邮件"
   //邮件内容
   text := "你好！"
   body := `
    <html>
    <body>
    <h3>
    "测试通过golang发送邮件"` + text + `
    </h3>
    </body>
    </html>
    `
   fmt.Println("send email")
   //执行逻辑函数
   err := SendMail(user, password, host, to, subject, body, "html")
   if err != nil {
      fmt.Println("发送邮件失败!")
      fmt.Println(err)
   } else {
      fmt.Println("发送邮件成功!")
   }

}
```