Feature request: exclude IP/network in allow_nets extra field

[Sami Ketola]

> On 30 Apr 2019, at 4.56, Zhang Huangbin via dovecot <dovecot at dovecot.org> wrote:
> 
> Dear all,
> 
> We use `allow_nets`[1] to restrict login clients, it works fine.
> Recently we need to allow some users to login from everywhere except some IP/networks, how can we accomplish this with "allow_nets"?
> 
> Tried allow_nets="!a.b.c.d", but Dovecot reports error "allow_nets: Invalid network '!a.b.c.d'".
> 
> Can we have this feature?


Just create another passdb for these premium users before the actual passdb and add skip = authenticated to the actual passdb.

Sami