[Techtalk] closed relay? (is that even what it'd be called?)

[Laurel Fan]

On Tue, Nov 20, 2001 at 06:25:23AM -0800, Conni wrote:
> My husband uses Mac, and he's using Eudora as his mail client.  I've got
> RedHat 7 on my machine, and I'm using exim to send mail (MTA?  I get
> really confused around this stuff.)  We have RoadRunner, and he uses RR's
> mail server to send his mail.  Can I configure exim to relay from his Mac?

Yes, you can.  If you want exim to send mail from his Mac to arbitrary
machines (outgoing relay, I believe), you want to add the Mac's IP or
hostname to the host_accept_relay option; use something like
host_accept_relay = mac's.host.name
Or, to allow relaying from any local machine, put in the range of IP's
that your router assigns, like:
host_accept_relay = 192.168.0.0/24

(for anyone not familiar with that notation, the above line indicates
the IPs from 192.168.0.0-192.168.0.255; in words, it means something
like "all the IPs where the first 24 bits are the same as the first 24
bits of 192.168.0.0".  Conveniently, each of the 4 numbers separated
by dosts is 8 bits [which is why 255, 2^8-1, is the highest possible
number], so 24 bits means the first 3 numbers).

For a more in depth explanation of host_accept_relay and other
exim-relaying-related stuff, see the exim info manual (info exim), go
to the "Other policy controls on incoming mail" section, and then its
"Control of Relaying" subsection.