I've central e-mail server. Other servers does not need to operate as a mail server. How do I configure Sendmail as submission-only e-mail server (mail client) under CentOS / Fedora / RHEL / Debian Linux / UNIX like operating systems?
Sendmail or any MTA can work in two different modes. It can accept incoming SMTP e-mail requests and send mail from the local machine / workstation or server (cluster node). This is called outbound MTA and it always runes in a queue-only mode.
Step # 1: Disable Sendmail Daemon In a Listing Mode
Edit the file /etc/sysconfig/sendmail using the text editor such as vi, enter:
# vi /etc/sysconfig/sendmail
Modify the line:
DAEMON=no
Save and close the file. Setting DAEMON=no tells Sendmail to execute only the queue runner on this machine, and never to receive SMTP mail requests on port # 25.
Step #2: Configure Mail Submission
You need to tell sedmail about a central MTA which will accept mail on port # 25 for all your domains. For e.g. mail.nixcraft.net act as a central MTA. Edit /etc/mail/submit.cf, enter:
# vi /etc/mail/submit.cf
Find the line beginning with D{MTAHost}, and update it to read as follows:
D{MTAHost}mail.nixcraft.net
Save and close the file. mail.nixcraft.net is the hostname of the server to which this machine should forward its all outgoing mail. Please note that mail.nixcraft.net must be configured to accept mail from your other workstations or server. Once done reload sendmail.
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{ 7 comments… read them below or add one }
I’m using my own sendmail server like cyberciti.biz as MTA(outbound) and if I need to relay mails of host cyberciti2.biz what settings need to be adjusted in cyberciti.biz host ?
nice tip, but what if I need to use non-standart port and authorization?
Hi vivek,
will this work for
-SMTP authenticated mail servers as well
-SSL/TLS supported mail servers
-Mail servers not running on port 25.
The server in question is google hosted mail server. Can you give any links which details how to point local sendmail to our gmail server to send outbound mails.
How can I create SMTP Authentication in Linux mail server via Sendmail package
How can i create Mail server (send mail & recieve mail) ?
Thanks man!!! Awesome tip..Exactly I was looking for..I only needed to option two make it a mail client use a remote server as the outgoing mail server..Thanks a lot!!!
Ho to do it with postfix?