This document describes 4 easy steps to setup your Sendmail email server as smarthost to relay on DNS Exit mail relay server for all email sending.

The mail relay service from DNSExit.com can be found here

For Sendmail V8.12 and above

1. Set your authorization informations by putting the following line to /etc/mail/authinfo file:

AuthInfo:relay.dnsexit.com "U:USERNAME" "P:PASSWORD" "M:PLAIN"

	Note: Replace USERNAME and PASSWORD with the DNSEXIT mail relay username and PASSWORD.

2. Add following lines to /etc/mail/sendmail.mc (check if apropriate settings doesn't already exists):

define(`SMART_HOST', `relay.dnsexit.com')  
FEATURE(`authinfo')
  
3. Update sendmail.cf and access.db files:   

# cd /etc/mail  
# m4 sendmail.mc >sendmail.cf  
# makemap hash authinfo < authinfo 
   

4. Reload or restart sendmail:  
# /etc/init.d/sendmail restart

For any version of Sendmail

1. Set your authorization informations by adding following line to /etc/mail/access file:

AuthInfo:relay.dnsexit.com "U:USERNAME" "P:PASSWORD" "M:PLAIN"

   Note: Replace USERNAME and PASSWORD with the DNSEXIT mail relay username and PASSWORD.

2. Add following lines to /etc/mail/sendmail.mc (check if apropriate settings doesn't already exists):

define(`SMART_HOST', `relay.dnsexit.com')  
FEATURE(`access_db')
  
3. Update sendmail.cf and access.db files:   

# cd /etc/mail  
# m4 sendmail.mc >sendmail.cf  
# makemap hash access <access 
   

4. Reload or restart sendmail:  
# /etc/init.d/sendmail restart

Note: If it does not work, you need to make sure the saslauthd is running on the server. saslauthd is the daemon for sending authentication . You may issue "service saslauthd start" to start the service.