**Why are there bounces for users who aren't subscribed?**

Most often, this is due to subscribers whose accounts forward mail someplace else and that final destination is broken.  This delivery failure generates a bounce that Ecartis sees as coming from someone who isn't on the list, since, after all, //that// address isn't.

Another common cause is SPAM being sent to the -bounce address.  Whatever the SPAMmer decides to drop in as a "From" address becomes listed as bouncing.  

These "notsub" bounces can be safely ignored.