How to configure sendmail to act as a mail gateway and relay mails???

Question

I installed the Solaris (Intel) v.8 (10/01) in my external network. Now, I want to configure it as a mail server and as a mail gateway between my internal mail host and itself.
I think I have read all documentation which comes in Answerbook2 about mail gateway.
I added some aliases to the aliases file in /etc/mail and executed the newaliases command.
The aliases pointed to my mail host which is in my internal network.
I included the IP address and the name of the mail host in the /etc/hosts
I can telnet the internal mail host and I can connect to it and verify the internal account thru:
mconnect "mail host"
vrfy "account"
But when I do
/usr/lib/sendmail -v "alias" < /dev/null
it translates the alias to the account in the internal mail host but it returns to me
"account" ... User Unknow.
When I try to use the mail server from one client in my internal network (I configure my mail client to use as Outgoing server the server in the external network) to send mails I receive the error:
550 5.7.1 Relaying denied. IP name lookup failed
I create a file called "access" and create the binary called "access.db" (makemap hash access < access), but it doesn�t work.
I think that maybe the sendmail.cf doesn�t recognize the access file but I�m not sure. I have worked with other "sendmail" version under others OS (RedHat Linux) but the files are quite differents.
Would you please help me?

Answer 1

I found the way to do it and this is the procedure
How to implement the mail gateway on Solaris 5.8
You have to make changes in 3 different places
1.- Files in /etc/mail (sendmail files)
2.- /etc/hosts file
3.- DNS files and /etc/nsswitch.conf file
1.- Files in /etc/mail
1.1.- Backup your existent sendmail.cf file and copy the main.cf file as
sendmail.cf (cp /etc/mail/main.cf /etc/mail/sendmail.cf)
1.2.- If you want to accept mail for entire domain in your mail gateway (your mail
server is an MX record in the DNS files), you�ll have to modify the sendmail.cf
file editing the line Dj as Dj$m or if you want to accept just mail for your specific
server you must put Dj$w.$m (be carefull to avoid spaces).
1.3.- Change in the sendmail.cf file the DM parameter adding ddn. It should
looks like DMddn (no spaces anywhere).
1.4.- Insert a line for the Dm parameter, which should include your domain
(ex.:Dmyourdomain.com, be care with spaces). If you have defined multiple
domains, add a line with Cm and put the domains one after other separated by
spaces. You have to put a space between Cm and the first domain
1.5.- Add the following rule in the ruleset, don�t use spaces, use tabs as
separator:
R$*<@$*.$+>$* $#ddn $@ $2.$3 $:$1<@$2.$3>$4 [email protected]
1.6.- If you find the following rule in the ruleset you should comment out it.
R$*<@$*.$+>$* $#$M $@$R $:$1<@$2.$3>$4 [email protected]
1.7.- If your host is receiving mail under different names for "local" delivery,
often you need to define those hosts in a "Cw" line and put the names one after
other separated by spaces. You have to put a space between Cw and the first
name.
1.8.- If you want to relay mails to different domains or subnets you can include
them into the file relay-domains. Each record in this file is a domain name (like
sun.com) or a subnet (like 192.0.0., be carefull with last dot).
1.9.- To test your sendmail service you have to stop and start it
(/etc/init.d/sendmail stop; /etc/init.d/sendmail start) and you can do the following:
1.9.1- To get basic debug information type:
/usr/lib/sendmail -bt -d0.1 < /dev/null
1.9.2- To test the conection:
mconnect "mail server"
vrfy "any alias"
1.9.3- To test the alias you inserted into aliases file (remember run newaliases
command after insert them).
/usr/lib/sendmail -v "any alias" </dev/null
2.- The /etc/hosts file:
2.1.- You must include in this file the IP address server, its nickname
(servername), its extended nickname (servername.domain), the word
"mailhost", the word "mailhost" and your domain (mailhost.domain) and the
word loghost.
2.2.- If you wish you can include all the servers that you want in the file. You
should do this is to avoid the use of DNS service translation.
2.3.- Check the DNS service thru nslookup servername (ex. Nslookup
sun.com), then test nslookup to your mail gateway
3.- DNS files and /etc/nsswitch.conf file
3.1.- Include a MX record for your mail gateway as the mail host for the entire
domain and verify that each record into the zone files include the MX record.
These files are in your DNS server (nameserver).
3.2.- Check your /etc/nsswitch.conf file. The record host must include files and
dns. It must look like
hosts: files dns