This article illustrates how to forward an email to a group of SMS recipients (using the SMS gateway)

Note that to use this plugin you need to download and install on the FoxBox the package "sqlite":

apt-get install sqlite

The first thing you have to do is to place the new script in /etc/sms/scripts (call it "email2smsgrp").

This is available here (right click to download).

Remember to make it executable, giving right permissions.
Then you have to replace the link to the older script in /etc/.procmailrc with the new one:

From: /etc/sms/scripts/email2sms
To: /etc/sms/scripts/email2smsgrp

/var/log/iterator.txt
/var/log/numbers.txt

Subject:
   TOsms

Body:
   From: YOURNAME
   To: GROUPNAME

   Text of the message 

Remember to activate the "SMS gateway" from the Control Panel.

The GROUPNAME needs to exist in the phonebook, so you need to associate at least one contact to it.

If you need both the features (forwarding to single numbers AND to groups) you have to add a new rule into /etc/.procmailrc instead of changing the old one.
With this second rule you could say to handle emails with "TOsms" using the script email2sms, and the ones with "TOsmsgroup" using the email2smsgrp.
Then, simply distinguishing the two cases using the email subject, your FoxBox will handle both.