[Pkg-exim4-users] Block *@example.com but allow name at example.com

[Jeroen van Aart]

I would like to know if there is an easy way to block all recipients for 
a domain that is configured in hubbed_hosts except for certain ones.

For example in hubbed_hosts I have:
example.com: smtp.example.com

And I want all emails to that domain to be either denied (or sent to 
/dev/null) execpt for user at example.com.

I am hoping there is an easy way to do this with a few configuration 
settings in Debian, as opposed to writing my own. But I haven't yet been 
able to find out if this is the case.

Thank you,
Jeroen