Spam with "from" address in my domain

Hi,

We are receiving lots of bounced email messages as the result of someone sending spam, and using an email address in our domain name as FROM address. The email address they use doesn't even exist, we received the bounced messages in the catch all address. I have now disabled catch all so we won't get these bounces anymore, but I am wondering if there is anything we can do to prevent spammers from using our domain name to send spam?

I have been doing some research and apparently there is nothing we can do about it, but maybe there is something and I didn't find it.

Regards,
Veronica

 

Thanks for the reply, Jonathan.