Someone is spamming "from" my domain.

[Corner_Tommy]

Hiya,

This afternoon I found out that there is a person spamming email accounts with my domain
in the from field. So I get all the 'Mail delivery failure' emails in my inbox. And my domain
gets a 'bad' name. Whats pretty bad because i use it for everything. ( online buying, submitting )
What can i do about this?

kind regards,

Tom van der Weele