account sending emails that arent from me

[Malissa]

My inbox is full of 50,000 or more since yesterday of mail delivery failures for sending out emails that I am not sending out.  Any way to stop this.  I have checked my sent folder and these messages aren't there or to people I even know.  Please help!!!!!!

[SKaero]

You should contact your mail provider to check and make sure your account hasn't been compromised and is sending spam. If the mail isn't coming from your server what your most likely seeing is backscatter spam https://en.wikipedia.org/wiki/Backscatter_(email)

[Malissa]

THOUGHT ROUNDCUBE WAS MY SERVER

[SKaero]

Roundcube is an application that can be installed on your server. Roundcube is NOT hosting your mail, providing you service, and as no access to your server.