Interesting list of responses, to my email... not seeing much to help Jeff and his initial question.
 
Spamarrest and other 'services' DO NOT play nice with lists and group emails.   I refer you back to my email reply to Jeff
 
Now, there are a couple of downsides....
 
1 - it causes problems with lists..   group email lists, where all kinds of unknow email addresses can pop up...   causes aggrevation and constirnation for the list members...  hence my email address for this list   email2013@k4ama.com    I'll just change this list address annually, and the email associated with this address do not go through spamarrest.
 
You guys are hating on spamarrest for issues it is not designed or intended to handle.  It should not be used for list participation...   it says it can be... but as you well know.. it just doesn't not work well.   People who try to participate in lists with an address that uses one of these services should be banned...  it will not work and you are right to reject them immediately.  Any tool will only perform well when it is used - by the operator -  within the confines of its intended purpose.
 
For eliminating spam on  an email address it works great.  Performs as represented and I am very happy with the service.  If you want to participate in a group email list, such as this... use an email address that does not go through spamarrest.
 
Now...  stop hating on spamarrest... it is the fault of the user not the service...  :)
 
Tony, K4AMA