sending too many mails maybe baned by your mail server,

so we can just save as drafts to bypass it.

#

whole script:

vim /etc/cron.daily/diabsk.sh

#

#!/bin/bash

# SETTING
TOEMAIL="bak@diavps.com";
PASSWORD="xxx"
COMMENT='blog database backup'
DIR='wordpress'
YYYYMMDD=`date +%Y%m%d`
SUBJECT='DiaBak_of_'${DIR}'_'${YYYYMMDD};

# END SETTING

TMP='/tmp/diabak/'${DIR}
ATTTMP='/tmp/diabakatt/'${DIR}

rm -rf $TMP
mkdir -p $TMP
cd $TMP

# Put files what you want to backup to $TMP

# Don't change anything below
rm -rf $ATTTMP
mkdir -p $ATTTMP
cd $ATTTMP

tar zcPf backup.tar.gz $TMP
rm -rf $TMP
split -b 10m -a 3 -d backup.tar.gz ${SUBJECT}.part
rm -f backup.tar.gz

for file in *
do
#echo $COMMENT | mutt -a $file -s $SUBJECT $TOEMAIL
java -jar SaveEmailtoDraft.jar -to xxx@qq.com -subject "$SUBJECT" -text xxx@vip.qq.com -smtphost smtp.qq.com -imaphost imap.qq.com -user "$TOEMAIL" -password "$PASSWORD" -filename "$file"
sleep 30s
done

rm -rf $ATTTMP    

how to use save file to draft only:

java -jar SaveEmailtoDraft.jar -to xxx@qq.com -subject 'new subject test' -text xxx@vip.qq.com -smtphost smtp.qq.com -imaphost imap.qq.com -user xxx@vip.qq.com -password xxx -filename /Users/galenzhao/Desktop/EmailDraft/lib/javax.mail.jar

prebuild release: jar file

and this is the java code:

import java.util.*;
import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.*;
import javax.mail.internet.*;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.Options;

public class SaveEmailtoDraft {
public static void main(String[] args) {

	String to = "ToEmail@XXX.com";
	//String from = "FromEmail@XXXX.com";
	String smtphost = "XXXX.XXXX.com";

	String imapshost = null;
	String imapsport = null;
	String user = null;
	String password = null;

	String filename = "C:/temp/bb.log";

	String subject = null;
	String text = null;

	// create the parser
	CommandLineParser parser = new DefaultParser();
	try {
		// create Options object
		Options options = new Options();
		options.addOption("smtphost", true, "");
		options.addOption("imaphost", true, "");
		options.addOption("imapport", "");
		options.addOption("user", true, "");
		options.addOption("password", true, "");
		options.addOption("to", true, "");
		options.addOption("from", "");
		options.addOption("filename", true, "");
		options.addOption("subject", true, "");
		options.addOption("text", true, "");

		// parse the command line arguments
		CommandLine line = parser.parse(options, args);
		smtphost = line.getOptionValue("smtphost");
		imapshost = line.getOptionValue("imaphost");
		imapsport = line.getOptionValue("imapport", "993");
		user = line.getOptionValue("user");
		password = line.getOptionValue("password");

		to = line.getOptionValue("to");
		//from = line.getOptionValue("from", user);

		filename = line.getOptionValue("filename");
		subject = line.getOptionValue("subject");
		text = line.getOptionValue("text");
		
	} catch (org.apache.commons.cli.ParseException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}

	Properties properties = System.getProperties();

	properties.setProperty("mail.smtp.host", smtphost);

	Session session = Session.getDefaultInstance(properties);

	try {

		Message message = new MimeMessage(session);

		message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
		message.setSubject(subject);

		BodyPart messageBodyPart = new MimeBodyPart();

		messageBodyPart.setText(text);

		// Create a multipar message
		Multipart multipart = new MimeMultipart();

		// Set text message part
		multipart.addBodyPart(messageBodyPart);

		if (filename != null) {

			// Part two is attachment
			messageBodyPart = new MimeBodyPart();
			// Add the attachment file path
			FileDataSource source = new FileDataSource(filename);
			messageBodyPart.setDataHandler(new DataHandler(source));
			String[] path = filename.split("/");
			messageBodyPart.setFileName(path[path.length - 1]);
			multipart.addBodyPart(messageBodyPart);
		}

		// Send the complete message parts
		message.setContent(multipart);

		properties.setProperty("mail.store.protocol", "imaps");
		properties.setProperty("mail.imaps.port", imapsport);

		session = Session.getDefaultInstance(properties, null);

		javax.mail.Store store = session.getStore("imaps");

		store.connect(imapshost, user, password);

		Folder draft = store.getFolder("drafts");

		draft.open(Folder.READ_WRITE);

		draft.appendMessages(new Message[] { message });

		System.out.println(draft.getFullName() + " has : " + draft.getMessageCount() + " Message(s)");

	} catch (MessagingException mex) {
		mex.printStackTrace();
	}

	//return 0;
}
}    

#

https://www.vpser.net/security/vps-auto-bakup-send-by-gmail.html https://www.codeproject.com/Tips/1084798/Save-Email-With-Attachment-in-Outlooks-Draft-Folde