Strange mailer daemon mail back. Have I been hacked?
Hi,
I am having several problems with email on job roller. To receive some mails (not receiving all) I installed a plugin
wp mail smtp.
Each time I receive an email now, I am receiving back a very strange mailer daemon mail back saying that the mails could not be sent to some emails that I have never seen and have nothing to do with my site.
What should I do? Have I been hacked??
Thanks