a mail sender can produce transmitter and send_email

send with string

```

let rt = tokio::runtime::Runtime::new().unwrap();

rt.blockon(async { //from:senderAccoun //smtpsite:use which website to send email //password:senderPassword(it can be origin password) let mailer = MailerSender { from: "sender@qq.com".tostring(), password: "".tostring(), smtpsite: "smtp.qq.com".tostring(), }; //sendmail params //sendemail(&self,reciever,emailtopic,content(it can be string and html),attachmentname,attachmentpath) //if dont send attachment,attachmentname and attachmentpath fill None let _sendresult = MailerSender::sendemail( &mailer, "1984850802@qq.com".tostring(), "hell".tostring(), "hello,surprise".tostring(), None, None, ) .await; });

```

send with html

```

let rt = tokio::runtime::Runtime::new().unwrap(); rt.blockon(async { let mailer = MailerSender { from: "sender@qq.com".tostring(), password: "".tostring(), smtpsite: "smtp.qq.com".tostring(), }; let _sendresult = MailerSender::sendemail( &mailer, "1984850802@qq.com".tostring(), "hell".tostring(), "

hello,surprisess

```

send content and attachment

```

let rt = tokio::runtime::Runtime::new().unwrap(); rt.blockon(async { let mailer = MailerSender { from: "1984850802@qq.com".tostring(), password: "sfckoixahcpodcbb".tostring(), smtpsite: "smtp.qq.com".tostring(), }; let _sendresult = MailerSender::sendemail( &mailer, "3502728398@qq.com".tostring(), "邮件".tostring(), "

hello,surprise