Re: rquayle(_at_)usa(_dot_)net cancelled for spamming?

Someone quoted the following:

<<< 551 <rquayle(_at_)usa(_dot_)net>... User cancelled for spamming

Is that a "normal" diagnostic to see from a mail handler?

I note that the copy I received had the following in the header:

From: Mail Delivery Subsystem 
<mailer-daemon(_at_)maxine(_dot_)nancynet(_dot_)com>

Kind of suspicious that the error message should come from 
one of the Ten Most Wanted Spammers.......