[BlueOnyx:15924] suspended email address still receiving

[Tom]

I have suspended email for several users on my server. However, the email 
to those users are still being received. Since I have other users that need 
to receive email under the same domain names, I cannot remove the email 
servers. 
Is this normal behavior or is this a bug or error of some sort, allowing 
email to still be received to a suspended account, instead of being bounced?
Thanks in advance.
Tom