I have an e-mail gateway machine which relays e-mail to a machine on our
internal network and also relays e-mail from this machine to our ISP's
smart host. I have the gateway machine set up with a dial-on-demand
connection to our ISP so, to minimise the amount of connection time, I have
exim set up to hold all remote mail in the queue, which is then run every
half hour. Mail is held in the queue using hold_domains_except, so that
inbound e-mail is not held in the queue but is relayed on immediately.
The problem I had was that my smart_route router had its route_list
attribute set to "* post.demon.co.uk bydns". This meant that every time
someone from within our organisation sent some external e-mail, it was
correctly held in the queue, but exim used DNS to look up post.demon.co.uk,
meaning that the gateway machine had to dial out to do a DNS lookup. This
was obviously unsatisfactory, so I put post.demon.co.uk in /etc/hosts and
changed bydns to byname. This works OK until the ISP temporarily changes
the IP address of its smart host in order to do maintenance work, and we
are refused a connection to the original smart host.
So what is the correct way to do what I am trying to do, i.e. stop exim
trying to resolve post.demon.co.uk at the time that it receives the e-mail
for relaying, but still uses DNS at the time that the queue is run?
Thanks,
Jonathan Hazan
Datix Business Systems Ltd
London, UK
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*** Exim information can be found at
http://www.exim.org/ ***
