Spammers 'hijacking' nozell.com domain

It looks like some spammer is using my domain name as for the return
address. Starting yesterday I started getting a bunch of bounced email
allegedly from addresses like this:

Here is a selection of the crap that they are sending out:

To: 

Subject: Re: fioricet, soma, buspar, prozac, and more prescribed
         online and shipped to your door jnk ngc vktv lsgqp uredu jb r
         nclh qovnbcdpzdvygvotdzljdt yqlis pvhq diijybv djkxitmhw xksh
         h

To: 

Subject: Fwd: get prescription meds to your door - no prior
         prescription needed rbthixw juminx wuzeh y m kywdghdyb tt xx
         dfzlztjajjzhz lyhnjufi omhb tsntghowomc gjm guuhleytw

To: 

Subject: Re: get prescribed viagra, diet pills and much more online!
         overnight shipping id pjvunfslev daqrksw qck lrrpqarma tlpkb
         ym q tu nk bgl lsc pmppwvlxiageo

To: 
Subject: Fwd: ever wanted real soma pills   rrvkmqjohenzzvowgseyb

To: 

Subject: Re: order status
         (%random_number%random_number%random_number%random_
         number%random_number%random_number) fph mbnyhhpbequue zaty
         zlhifzh ivb wdgfhbkgoyaw rjoslyduhrh xhrzphcp kbl
         aitqveaefytihoir lghshjqs 

The last one is interesting because it looks like the jerk messed up
his spamming software.