Mark Goodge:
> If the value for mynetworks is contained in a file rather than hardcoded
> into main.cf, as per this example from the documentation...
>
> mynetworks = $config_directory/mynetworks
>
> ... is it necessary to reload Postfix when the contents of that file
> changes, or will any changes be picked up immediately?
Like main.cf, the file is read once. If it needs to change often,
use something like:
mynetworks = hash:$config_directory/mynetworks
and update the database as described in
http://www.postfix.org/DATABASE_README.html#safe_db
(Postfix will detect the database change and restart automagically).
Or use rsync (which does the rename implicitly).
Wietse
