qmail help on forwarding with smtproutes

Hi

I have a scenario where I need to implement the smarthost concept with
qmail to prove qmail can do anything sendmail can.

In my dns server I have an mx record that does not host record
associated to it. But I have three cname records , so when I do a
type=mx and type by the mx record entry I get a list of cname records
that are actually my host with a preference , the whole idea being
that when one server goes down it shoud be transparent to my qmail
server as to figure out which host to use ( like a load balancer ).The
host record with the lowest preference value is the first one to be
chosen.

I have created a smtproutes file and in this I have an entry which
says

:mailhost.domain.com ,.

The problem that I see is that when my application uses qmail to
forward all emails to another mail server by looking underneath the
mailhost.domain.com it says it could not connect to the mailserver as
its tryint to do a telnet to amilhost.domain.com 25 , what I want to
do is to make it do a lookup on this MX record find a host with the
lowest preference , choose it and connect to it to send out emails

Thanks in advance to everyone who will help me solve this problem

r> what I want to do is to make it do a lookup on this MX record [...]

"smtproutes" is a mechanism for overriding the contents of the DNS database
(when the SMTP Relay client is looking up what SMTP Relay server to contact).
If you want your system to use what is in the DNS database, then don't tell it
_not_ to do so.

rk_kathuria@yahoo.com (raman) writes:

> I have created a smtproutes file and in this I have an entry which
> says
>
> :mailhost.domain.com ,.

What's this -----------^

> The problem that I see is that when my application uses qmail to
> forward all emails to another mail server by looking underneath the
> mailhost.domain.com it says it could not connect to the mailserver as
> its tryint to do a telnet to amilhost.domain.com 25 ,

No, qmail doesn't "telnet" to other hosts. The problem is that it's
doing a CNAME lookup on the specified domain name.

> what I want to
> do is to make it do a lookup on this MX record find a host with the
> lowest preference , choose it and connect to it to send out emails

Patch qmail-remote.c. Search the qmail list archives and qmail.org
first, though, because someone else might have already done this.

--
Dave Sill Oak Ridge National Lab, Workstation Support
Author, The qmail Handbook <http://web.infoave.net/~dsill>
<http://lifewithqmail.org/>: Almost everything you always wanted to know.