One sugestion.
I'm have a configuration on my postfix.
....
check_helo_access pcre:/etc/postfix/helo_deny ....
in etc/postfix/helo_deny have:
/.*@*\.be$/ REJECT HELO DOMAIN DENIED
/.*@*\.tw$/ REJECT HELO DOMAIN DENIED
/.*@*\.fm$/ REJECT HELO DOMAIN DENIED
....
The mxhero not let me address something like: @.edu.* or @.info*
It would be interesting to work with regular expressions.
[]s
Other idea!
Load from file...
=P
Ok, we were afraid of been to technical if we used regex, but we will give it a look.