Sendmail outbound mail routing according to sender

[mecca]

Hi,

First post - hope I dropped it in the right place :D

OK, we're using Sendmail on RHAS 4 and all of the mail up till now has been local / internal only; this has negated the need to pass it through our spam filter/mail gateway etc. We now need to route some mail to external domains, which means it must go through the filter; similarly all messages originating from localhost address should continue to use the current configuration.

So, my question is this.....

Can we configure Sendmail to send mail that originates from a particular address out via a specific smarthost/relay? The from address would be formatted as a valid internet mail address (e.g. first.last@ourdomain.com).

If (and I really hope the answer is yes) this is possible, what is the best/easiest/safest/quickest way of achieving this? I'm not very familiar with sendmail.cf syntax etc., so answers in "configuring sendmail for dummies" format would be greatly appreciated!!

Thanks in advance for any help,

Mark.

[topdog]

Hi,

First post - hope I dropped it in the right place :D

OK, we're using Sendmail on RHAS 4 and all of the mail up till now has been local / internal only; this has negated the need to pass it through our spam filter/mail gateway etc. We now need to route some mail to external domains, which means it must go through the filter; similarly all messages originating from localhost address should continue to use the current configuration.

So, my question is this.....

Can we configure Sendmail to send mail that originates from a particular address out via a specific smarthost/relay? The from address would be formatted as a valid internet mail address (e.g. first.last@ourdomain.com).

If (and I really hope the answer is yes) this is possible, what is the best/easiest/safest/quickest way of achieving this? I'm not very familiar with sendmail.cf syntax etc., so answers in "configuring sendmail for dummies" format would be greatly appreciated!!

Thanks in advance for any help,

Mark.
The way i see it is that all your intranet mail is being handled by the sendmail server so there is no need for it to leave your network may destined for any other addresses is the one that will go out of the smarthost.

For the sendmail cf you need this

DS smart_host_name


You can also use the sendmail mc system which is easier

define(`SMART_HOST', `smtp.your.provider')dnl


Then type make inside /etc/mail

[mecca]

Thanks for the reply!

We eventually got it working by adding the "from" addresses to the sendmail.mc file :-
EXPOSED_USER(`first.last')
..and also by adding the relay host in the mailertable file along with the allowed external domains :-
external-host.com esmtp:spamfilter.ourdomain.com
ourdomain.com esmtp:spamfilter.ourdomain.com (for NDR's etc!)

Obviously, if we need to allow additional external domains, we've gotta add them verbatim to the mailertable file, but hey, it's a step in the right direction (and a solution had to be in place by Monday, so we were pretty close to the wire ;)).

Cheers,

Mark.