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?
For those who prefer a longer question, with more background behind it,
the reason I'm asking is because the server on which Postfix is running
is the outbound relay for a network on an IP which changes regularly. So
I want to update mynetworks automatically when that IP changes.
I know I could solve the problem by using authentication, but a lot of
the outbound email is generated by cron scripts on a server inside the
network, and rewriting all of them to authenticate when sending mail is
likely to be considerably more effort than updating mynetworks as and
when the IP changes.
I already have a system which changes the destination of inbound mail
via transport maps, using a MySQL table that is updated from inside the
network - whenever it detects that its public IP has changed, it changes
the destination value to be that IP. That's fine for inbound mail, as
there's only ever one IP address in the lookup table. But outbound mail
requires more than one IP in mynetworks, and also currently has a mix of
single IPs and subnets (since the server is a relay for more than one
location). So a MySQL lookup table would be more problematic as making
that handle CIDR lookups is non-trivial.
The best solution, therefore, seems to be to store mynetworks in a flat
file, and just update its contents when the public IP of the network
changes. That's a relatively simple programming task. But then the
question is, do I need to reload Postfix when I update the contents, or
will changes be picked up automatically?
Alternatively, given this background information, can anyone suggest a
better way of achieving my goals?
Mark
--
My blog: http://mark.goodge.co.uk
