On Fri, 9 Jan 1998, John Horne wrote:
> Just checking something:
> Our central mailhub has the IP address 141.163.2.62, but the name as set by
> "primary_hostname" is 'pandora.computing-service.plymouth.ac.uk'. However,
> the DNS shows 141.163.2.62 to be "plymouth.ac.uk" which is the domain pandora
> looks after (confused?).
Not very. But why do you do this when all you need is
plymouth.ac.uk. MX 5 pandora.computing-service.plymouth.ac.uk.
(which is the sort of thing other places do)?
However, be that as it may...
> In trying to allow plymouth sub-domains to relay through us, I included
> 'relay_domains_include_local_mx'. But is the MX check done on the local host
> name (pandora) as set in 'primary_hostname' or by the DNS domain name for the
> IP address (plymouth in our case)?
Neither. That option allows relaying *to* any domain name whose MX
records points to your local host ("incoming" relay). For example:
any.other.name MX 4 pandora.computing-service.plymouth.ac.uk.
It is as though any such domain were included in relay_domains.
You, on the other hand, are trying to permit "outgoing" relay *from* a
set of hosts. That is controlled solely by the
sender_{host,net}_{accept,reject}_relay options. [NB: "incoming" is
controlled by domain; "outgoing" by host.]
Isn't something like
sender_net_accept_relay = 141.163.0.0/16
what you want?
This does seem an area that causes confusion. I rewrote section 40.4 for
the latest manual to attempt to make things clearer. At the time I
wondered whether I should include a diagram of some kind. Perhaps I'll
try to dream one up for the next edition.
--
Philip Hazel University Computing Service,
ph10@??? New Museums Site, Cambridge CB2 3QG,
P.Hazel@??? England. Phone: +44 1223 334714
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