Re: [cobalt-users] Mail relaying

[Brent Sims <brent@xxxxxxxxxxx>]

On 8 Jun 2000, Simon Billis so wrote:

} I would like to be able to set up my Raq3 as a mail relay host
} for some domains that  already have smtp mail hosts. All I want to
} do is to accept mail if their server is down and forward the mail
} when the server comes back up. 

	You need to use Sendmail's mailertable to do this and the
RaQs don't have one. I haven't bothered to check to see if M4 is
installed (you need it to generate sendmail.cf files, that is, of
course, unless you can write sendmail rules).

	At the very least, you'll need to generate or write (don't
try this at home) a sendmail.cf file which includes mailertable
access, The mailertable is a database so it would need to be hashed
after each change so you'll need to set that up too and you'll 
have to hand tweak the zone files on both ends in order to set 
things up and you'll have to add things like a separate queue
directory which is automatically enabled if the primary mail
exchanger goes down for as goes down for an extended period of time,
messages will start bouncing unless you move them out of the live
queue. Then you need to be prepared for the worse...

	I run backup mail servers for another web hosting company
here. If they go down all the mail ends up being queued here. It can
very quickly add up to huge amounts of data that - particularly if
their are dialup users in the mix who have Cable/DSL connections as 
they tend to exchange mulitimegabyte messages as a matter of
course. The end result is that all the mail just sits there taking
up space and eating up system resources on your machine.

	This is just my opinion, mind you, but I wouldn't recommend
even trying to do this on a machine which is used for much else
unless you are absolutely sure the load will be light and you at
least read the details on how to do this in DNS and Bind by Paul
Albitz & Cricket Liu and have at least scanned the applicable rule
set explanations in the Bat book.

	Peace be with you,
	
	Brent
	
	Brent Sims
	WebOkay Internet Services
	http://www.WebOkay.net
	Brent@xxxxxxxxxxx
	(719) 595-1427 (Voice/Fax)