I need to send email from RHEL host running 6.3 to my microsoft exchange email ID. Can any one please help me with detail steps for the configuration. I am new to Linux so tried some steps from webpages but not succeeded.

I have done the configuration as follows:

  1. Edited '/etc/mail/local-host-names' with my Linux server fqdn.

  2. Edited '/etc/mail/access' and as below:

Connect:mailserver.xxx.com RELAY
Connect:mailserver RELAY
Connect: RELAY

  1. makemap hash /etc/mail/access.db < /etc/mail/access

  2. Edited /etc/mail/sendmail.mc as below:

dnl DAEMON_OPTIONS(`Port=smtp,Addr=, Name=MTA')

  1. m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf

  2. Service sendmail restart

At this stage all service started ok

[root@xxx mail]# service sendmail restart
Shutting down sm-client:                                   [  OK  ]
Shutting down sendmail:                                    [  OK  ]
Starting sendmail:                                         [  OK  ]
Starting sm-client:                                        [  OK  ]

Now I tried to send email:

mail -s "Test Email"  [email protected] < /dev/null
Mail sent successfully but not delivered to mail ID.

[root@xxxx mail]# mailq
/var/spool/mqueue is empty
                Total requests: 0

But I am not able to receive any email. In /var/spool/mail/root it shows its sending mail but not able to deliever. Will keep trying for 5 days before giving up.

Appreciate any support to fix this issue.

  • What exactly do you need? Simply configure sendmail such that messages from your server to [email protected] get delivered? Or should all outgoing message, to any address, get redirected so that messages such as to bob@ServerFault and to [email protected] end up in your mailbox on the Exchange server? Or should the exchange server be used as the outgoing smtp server, the smarthost in jargon?
    – HBruijn
    Aug 5, 2015 at 12:25
  • Yes, I need to simply configure sendmail to send messages from my server to my email id [email protected] Also need to send email from an automated script of OracleDB to few users. HBruijn
    – syed
    Aug 9, 2015 at 7:21
  • 1
    Typically /var/log/maillog will give some hints on why the message is rejected.
    – HBruijn
    Aug 9, 2015 at 9:12
  • [root@xxxxxx~]# echo hello |sendmail -v [email protected] xxx.com: Name server timeout [email protected]... Transient parse error -- message queued for future delivery [email protected].. queued HBruijn
    – syed
    Aug 9, 2015 at 10:12
  • The hint is: Name server timeout - That indicates that the resolver you've configured isn't responding, check the settings you used in /etc/resolv.conf
    – HBruijn
    Aug 9, 2015 at 11:47

2 Answers 2


From your latest comment:

The following addresses had permanent fatal errors ----- ----- Transcript of session follows ----- 550 5.1.2 ... Host unknown (Name server: xxx.net: host not found)

Seems a clear indication of what's wrong. You have resolving problems.

Either your name servers are not configured correctly. Check your /etc/resolv.conf and from the commandline with for instance with nslookup -type=mx example.com

# Sample /etc/resolv.conf using Google's public DNS

Alternatively the name-servers you are using are not capable of resolving your domain, for instance because they are not recursive..


[root@xxx ~]# nslookup -type=mx xxx.net

Server: xx.xxx.xx.10 Address: xx.xxx.xx.10#53

*** Can't find xxxx.net: No answer

****Sendmail didn't worked for me... atlast I sent email using postfix:****


Edit /etc/postfix/main.cf

Below the relayhost examples, add this line:

relayhost = smtp.xxx.com

Restart postfix:

/etc/init.d/postfix restart Sendmail:

Edit /etc/mail/sendmail.mc

Change: dnl #(SMART_HOST',localhost')dnl

To: (SMART_HOST',smtp.xxx.com')dnl

Save the file, and from the /etc/mail directory run "sudo make"

Restart sendmail /etc/init.d/sendmail restart

sendmail -v [email protected]

Mail working and recieved

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