[Dovecot] Domain blacklisting

[Thomas Hummel]

Hello,

I run dovecot-2/Maildir/LDAP user/passdb and would like to be able to deny
acess to users who connect from certain domains/IP (google.com for instance
since in that case they gave their credentials to a third party).

My understanding is that I cannot use some negative form of "allow_nets". The
only mechanism I can think of is tcp_wrappers. However, dovecot documentation
mention it only in the dovecot-1 section. Does it work the same way with dovecot-2 ?
Is it a bad idea (I'm thinking of the induced overhead) ?
Can you see another way to blacklist (at dovecot application level) some sources ?

Thanks 

-- 
Thomas Hummel 	    | Institut Pasteur
<hummel at pasteur.fr> | Pôle informatique - systèmes et réseau