dma aliases to a file (/dev/null)

Have a bit a hard time finding this via google and the man pages, but is 
it possible to have

bit-bucket: /dev/null

in the /etc/aliases file with DMA ?


# mail -v bit-bucket
Subject: testing to null

.
EOT
sendmail: invalid recipient `bit-bucket'

# grep bit-bu /etc/aliases
bit-bucket: /dev/null
dev-null: bit-bucket


If I change /dev/null to a valid user it works. It implies I cant 
redirect to a file or just discard mail ?  Is there a different DMA 
command / config to discard mail sent to a certain user ?