Right before Thanksgiving, I starts getting a lot of return email which I do not know where they are from and I do not know those people.  It is use my company email address on behalf of the Walgreen, Walmart, target etc... to sent out those emails.  I try to fix it, but I do not know how. I have geek squad help me to check, and change log in and change IP address, but use less.

One day, my friend help me to find out, it was someone use my email address sent out the php mailer.  Please let me know how to fix it.