Getting huge emails

Hello, I am getting huge this type of message. It is returning emails sent by my server but not by me. I don’t know who sent this using my server. Please help me to stop this. I think my cyber panel server was hacked. Please help me to get out of this.

Are you sending emai lists? What is message content on those mails?

I didn’t send any email

Have you used any nulled pirated/nulled themes on your websites? Also post content what’s on bounce mail.

I didn’t. But, my website was hacked some days ago and I recovered that.

Can you post content of that mail and mail logs those would help…

According to my knowledge, For this reason, is coming this type of email your SMTP server details someone used to send emails, but the email addresses are not valid or You are using SMTP to send emails and your email addresses are not valid. you can see this type of “Undelivered Mail Returned to Sender” emails. To fix this issue you need to change your email password or delete the email address and create a new one.

This is an example for you. Some bots are trying to register on the website. But their given email address is fake. but the website email service tries to send the verification emails. That is the reason to receive this type of “Undelivered Mail Returned to Sender” email.

Exactly what happened. More than 8000 emails sent on different Yahoo emails with a link. After that, all were rejected due to high spam.

But how I insure that my websites and server are fine. I changed every password related this server, and hosted websites on it.

All are rejected mail because of high spam. More than 8000 emails send by my server and most of them blocked.

WordPress website or Custom website?

WordPress website

You can use Spam Protection, AntiSpam, FireWall this plugin.