Question about sendmail...

[Alexander Dalloz]

Am Fr, den 28.10.2005 schrieb Philip Prindeville um 4:26:

> I'm running FC3 (updated) on a handful of machines.
> 
> I have a single IP address, with a NATing router set to that
> address.  I have a domain, and an MX which points through
> the router at my mail server (or rather, the router is configured
> to port-forward 25, 143, etc to the mail server).
> 
> I also have several mail clients on my 192.168.1.x network.
> 
> The issues are the following:
> 
> * the clients have a smart host (DS) defined as the mail relay,
>    but they canonical its name and then look it up in the DNS,
>    trying to contact it on the external IP address (and not its
>    internal 192.168.1.x address in the /etc/hosts file).  My
>    /etc/nsswitch.conf file is unmodified.
> 
> * the clients then try to relay the email with a sender's envelope
>    address as user at host.my-domain, which the relay rejects
>    because "host.my-domain" doesn't resolve in the DNS.
> 
> * I should probably have define(`LOCAL_RELAY', `:$S') to
>    handle forwarding everything to the mail server.
> 
> I used to know all of this stuff once upon a time...

> -Philip

Reading this I have the strong feeling it was you I was talking to in
#sendmail on freenode this evening (night) :)

I would vote for running a local DNS (bind) service, in conjunction with
DHCP and dynamic zone updates. That would be ideal. And for unqualified
sender addresses use the masquerading features of Sendmail.

On the other hand you may go this route: do not run local Sendmail
daemons, but use the submission process to directly feed outgoing mail
from inner clients to the central mail hub. Have a look at
/etc/mail/submit.mc. Comment out (remove the leading "dnl") for

define(`confDIRECT_SUBMISSION_MODIFIERS',`C')

and even add a line

FEATURE(`nocanonify', `canonify_hosts')

and finally change the IP in

FEATURE(`msp', `[127.0.0.1]')dnl

to the one of the central mail hub.

Please see http://www.sendmail.org/m4/msp.html or better the current
cf/README coming with your Sendmail on Fedora. Many discussion about
this topic to be found through

http://groups.google.com/groups?hl=en&lr=&c2coff=1&sa=X&oi=groupst&q=Sendmail+confDIRECT_SUBMISSION_MODIFIERS

Hope it helps.

Alexander


-- 
Alexander Dalloz | Enger, Germany | GPG http://pgp.mit.edu 0xB366A773
legal statement: http://www.uni-x.org/legal.html
Fedora Core 2 GNU/Linux on Athlon with kernel 2.6.11-1.35_FC2smp 
Serendipity 06:01:53 up 6 days, 10:02, load average: 0.37, 0.23, 0.18 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: Dies ist ein digital signierter Nachrichtenteil
URL: <http://listman.redhat.com/archives/fedora-list/attachments/20051028/e04ec82c/attachment-0001.sig>