sendmail

1.sendmai forward setting.

sendmail.cf (sendmail.mc) , you can change SMART_HOST’s behaviof by using “[“.

[example] If you wanto to make sendmail forward always to mailserver.hoge.com, you should write the setting as follows.

DS[mailserver.hoge.com]

If you don’t use “[“, sendmail will decide the forward destination by searching MX record.

so It is no guarantee to forward mailserver.hoge.com.

2. stop forwarding except for specific domain.

(1)add alias

#echo 'trash: /dev/null' >> /etc/aliases
#newaliases

(2)modify mailertable

#vi /etc/mail/mailertable
hoge.jp.com	smtp:[forwarding mail server]
.	local:trash
(using "[ ]" to avoid searching MX record )

(3)convert mailertable

#makemap hash /etc/mail/mailertable < /etc/mail/mailertable

(4)resart sendmail

#/etc/rc.d/init.d/sendmail restart

3. If you could’t access DNS, and you want to forward another SMTP by sendmail.

make /etc/mail/service.switch. and write down as follows.

hosts  files