[Mailman-Users] Mailing list commands being limited?

[Brian Herold]

We have an automated system that programmatically adds users to lists using the email command functionality (subscribe nodigest address=$theemailaddress).  Though, some of the lists are large and occasionally we get the returned email response:
 
"We have received a message from your address `the at sender.com' 
requesting an automated response from the
the-list at lists.com mailing list.  We have seen 10 such
messages from you today.  In order to avoid problems such as mail
loops between email robots, we will not be sending you any further
email responses today.  Please try again tomorrow.
 
If you believe this message is in error, or if you have any questions,
please contact the list owner at
the-list at lists.com." 
 
*Note that I renamed the sending and list email addresses.
 
Is there some limit that's being triggered causing this message, and what can I do to prevent it?
Thanks,
Brian