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Sendmail Routing or Gateway

Posted on 2000-01-15
Medium Priority
Last Modified: 2010-05-18
I have the following Intranet:

        Linux Box
  +----------+-...     --+
  |             |             |
  |             |             |
PC_1       PC_2...    PC_n
W98        W98       W98

Everything is up and running, like, fetchmail, DNS, Squid, Firewall. But one thing I could not run is sending an e-mail from my intra.net to  extra.net (such yourself or u_name@zipmail.com.br)
Can some one help me on this sendmail routing ? I have never worked w/ sendmail before, so I am kind of lost here.
I have searched some local bookstores and the internet with no good luck.
Remember that from the Linux box I can send any e-mail w/ no problem. What I want is how to route the PC's e-mail trhu the intra.net to the world (extra.net for instance) ? How would the sendmail.cf be configured?

Question by:kolotelo

Expert Comment

ID: 2358920
If you are after a book - the Sendmail book published by O'Reilly ( commonly known as the 'bat book' ) is the bible. It's a thick book, but it covers the setup of all things sendmail. It's co-written by Eric Allman, sendmail's programmer

It will explain how to do anything with sendmail - although you have to be willing to experiment ( and test!!! ) a bit.

I've just checked Amazon - search for 'Sendmail', and pick the book by Eric Allman & Bryan Costales, $31.96

Expert Comment

ID: 2359446
What is ur sendmail version ?
try this:

Go to /etc/mail
here is a file called acces. If not, create it.
then edit this file and add the following line:

xx.yy.zz      RELAY

(xx.yy.zz is ur network addr; if your network is, then put 192.168.0)
then save and then do :
makemap hash access < access

Then restart and try.

Hope this helped,


Author Comment

ID: 2360035
Thanks Sirs,
As I told you before, everything is runnin along ok. Sendmail ver is 8.9.3. /etc/acess is ok too.
I am using fetchmail w/ my ISP w/ no problem at all. The only thing I still can not do is to make my local intra.net delivery mails to outside.com.  Not from the linux box nor from the PC.
I live overseas an to purchase the O'Reilly book would take a month or so. I would appreciate some one to help me by this week. Attached is my sendmail.cf changes:

I will try the DR and DH, but I still need help.


Expert Comment

ID: 2360788
What does you /var/log/mail file say when you try and send some mail from one of the client machines to an outside host?

Accepted Solution

wmead earned 100 total points
ID: 2363404
To make your Linux server an email relay server you need to do the following:

1) Set it up as a DNS server or make sure that it can resolve all outside DNS queries

2) include the following entry in /etc/sendmail.cf
FR-o /etc/mail/relay-domains

3) include the domain name of the originating ip-address(es) that are sending e-mail. This will allow sendmail to relay the messages to the outside world. By default newer versions of sendmail do not allow relaying by default.

I hope that this helps somewhat.

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