Re: [cobalt-users] Mail relaying

[Jeff Lasman <jblists@xxxxxxxxxxxxx>]

Brent Sims wrote:

>         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).

I can write sendmail.cf <smile>.

I've been doing it a long time.  Until recently it was the only way I
ever configured sendmail.

>         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

I think all you really need is a higher cost (lower priority) mx record
for you system in the domain's primary DNS.

The mailertable has the routing information in it, as I recall.

And mailertable is no harder to has than is virtusertable; the
instructions have been posted on this list more than a few times
recently.

> 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.

Really?  While I like a separate queue, I'm not sure I remember this
from anywhere.  Can you expand a bit?

> 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.

So in other words I could get filthy rich offering this as a service,
right <smile>?

> 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.

I could set this up on a separate, medium-endowed RHL box here if
there's a market for it <smile>.

Jeff
-- 
Jeff Lasman <jblists@xxxxxxxxxxxxx>
nobaloney.net
P. O. Box 52672
Riverside, CA  92517
voice: (909) 787-8589  *  fax: (909) 782-0205