Subject says is all, right.  1.8b has this additional configuration
variable.  Not sure where to set it.  Here is the description of its
function in case you didn't know it was available:
 
"In some cases, it  may be desirable to filter a  certain set of addresses
 for  all lists,  especially in  the event  of temporary  problems with  a
 gateway.  This  can  now  be  done  with  the  FILTER_ALSO  configuration
 variable. It  has the same format  as the "Filter= Also,..."  list header
 keyword, except that the wildcard specifications are separated by blanks,
 not  commas. For  instance,  FILTER_ALSO =  '*@*.XYZ.COM *@ABC.COM'  will
 filter the addresses in question globally."