Forcing sendmail to use /etc/hosts before using DNS

[Ewald Beekman]

Probably you can use the mailertable feature to accomplish this,
make sure the feature is enabled in sendmail.mc :
FEATURE(`mailertable',`hash -o /etc/mail/mailertable.db')dnl

and create /etc/mail/mailertable with something like:
someserver.usu.edu      esmtp:[172.17.1.33]

do a makemap
makemap -v hash mailertable < mailertable

and a kill -HUP of your sendmail process:
kill -HUP `head -1 /var/run/sendmail.pid`

you can always check where sendmail is going to send stuff with the
-bv option:
/usr/lib/sendmail -bv myuser at someserver.usu.edu

http://www.sendmail.org/~ca/email/doc8.12/cf/m4/features.html

have fun!
Ewald...

On Mon, Jan 13, 2003 at 01:50:15PM -0700, John B. Hanks wrote:
> I am trying to get sendmail/mailscanner to do something that has me
> questioning my understanding of the way this has been working. Here is what
> I currently do to scan mail for a mail server.
>
> My MailScanner machines are noturus.usu.edu and ameiurus.usu.edu.
>
> If I want to scan mail for mail.dept.usu.edu, I go to that DNS record and
> add
>
> mail.dept.usu.edu  in mx  10 noturus.usu.edu
> mail.dept.usu.edu  in mx  10 ameiurus.usu.edu
>
> This has been working flawlessly for some time. I think what happens is mail
> gets delivered to the MailScanner machines, they recognize themselves as MX
> hosts and then forward the scanned mail to the A record for the target.
>
> Now I need to do some magic for a server move. I have a host,
> someserver.usu.edu, that wants mail scanned and delivered to another box
> which will host mail but someserver.usu.edu still has other functions so it
> need to keep this name in its a record. I thought I could accomplish this by
> adding entries to /etc/hosts on the mailscanners like
>
> 172.17.1.33      someserver.usu.edu
>
> So that when noturus or ameiurus looked up someserver.usu.edu they would use
> the entry from the hosts file and unwittingly deliver mail to the new
> server. But, sendmail seems intent on ignoring the /etc/hosts file. I have
> changed /etc/resolv.conf, /etc/nsswitch.conf, /etc/host.conf and
> /etc/mail/services.switch so that all these point to files first, then dns
> but it still isn't working. The ping command works as expected, checking
> /etc/hosts and using the IP address from the file. Can someone tell me if
> what I want to do is possible and if so, how do I get sendmail to behave
> this way? As we move more mailservers to use MailScanner this is going to
> come up again and I need a way to solve it.
>
> This is Redhat 7.3, MailScanner 4.11-1 and sendmail 8.11.6-15.
>
> Thanks,
>
> jbh

--
Ewald Beekman, Security Engineer, Academic Medical Center,
dept. ADB/ICT Computer & Network Services, The Netherlands
## Your mind-mint is:
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