http://www.faqs.org/docs/securing/chap22sec185.html
How to setup an E-Mail Relay Host with Sendmail?
http://www.cyberciti.biz/faq/configure-sendmail-as-a-smart-host/
http://www.cyberciti.biz/faq/force-sendmail-to-route-mail-to-specific-hosts-or-mailserver/
http://www.brandonhutchinson.com/Creating_a_new_sendmail_mailer.html
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/sendmail.html
http://www5.us.freebsd.org/doc/en/books/handbook/sendmail.html
http://www.planetlarg.net/open%20source%20cookbook/e-mail/send-message-remote-host-using-sendmail
http://www.faqs.org/docs/linux_network/x15291.html
http://www.sendmail.com/sm/open_source/tips/smtp_relaying/
http://www.active-server.com/blog/creating-an-open-relay-with-sendmail/
http://www.freebsddiary.org/relay.php
http://www.sendmail.org/~ca/email/relayingdenied.html
http://www.ozzu.com/unix-linux-forum/how-setup-relay-host-sendmail-t29690.html
What are the basic steps for working with sendmail configuration file?
- Edit the /etc/mail/sendmail.mc
- Regenerate the /etc/mail/sendmail.cf from the /etc/mail/sendmail.mc file
- sudo chmod 666 /etc/mail/sendmail.cf
- sudo m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
- sudo chmod 644 /etc/mail/sendmail.cf
- Restart sendmail
How can we regenerate /etc/mail/sendmail.cf from /etc/mail/sendmail.mc?
sudo chmod 666 /etc/mail/sendmail.cf
sudo m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
sudo chmod 644 /etc/mail/sendmail.cf
How can we restart sendmail?
sudo /etc/init.d/sendmail restart
How can we restart Sendmail in debug mode?
sudo /etc/init.d/sendmail restart -bD -O LogLevel=20 -X /tmp/sendmail.log
How can we verify your configuration by generating a deliverability report?
sudo sendmail -bv user@example.com
In this report, look for the following output:
user@example.com... deliverable: mailer awsemail, host example.com, user user@example.com
How can we to send a test email?
sudo /usr/bin/sendmail -f from@example.com to@example.com
Type your message and put a dot on a single line by itself or press CTRL+D. We can also create a test file to_internet:
To: martin.zahn@plenaxx.ch
From: martin.zahn@arkum.ch
Subject: Ein Test
Dies ist ein Header Test
(empty line)
and then do:
cat to_internet | /usr/lib/sendmail -bm -t -v
/usr/lib/sendmail -vt
How can we show the delivery agent (debug)?
/usr/lib/sendmail -d0.12 -bt < /dev/null
How can we show macros without $u, $M which will be set when mail is already delivered (debug)?
/usr/lib/sendmail -d35.9 -bt
How can we show sendmail queue?
/usr/lib/sendmail -bp
How can we test the MX-Record readed by Sendmail from DNS?
/usr/lib/sendmail -bt
How can we configure smart host?
Edit /etc/mail/sendmail.mc:
define(`SMART_HOST',`smtp.net4india.com')
How can we configure sendmail to relay mail through another server?
- Open up /etc/mail/sendmail.mc
- Search for SMART_HOST
- Remove the dnl (delete through newline) prefix.
- Save the file
- Regenerate the sendmail.cf file.
If you do not use m4, open up /etc/mail/sendmail.cf, search for DS, and update it to:
DS[192.168.4.11]
What is the purpose of mailertable?
mailertable allows you to route or deliver mail to different hosts. Edit /etc/mail/sendmail.mc to include:
FEATURE(`mailertable')
and edit /etc/mail/mailertable to include:
192.168. smtp:mail.myisp.com
nixcraft.com smtp:p5.mail4india.com
Now build database version of the mailertable is built using:
makemap hash /etc/mail/mailertable
Other useful debugging commands:
http://www.planetlarg.net/open%20source%20cookbook/e-mail/send-message-remote-host-using-sendmail
