Alternatives Program for MTAs

The alternatives program is a way to change the default mail server so that it will be Postfix. This program is only necessary for CentOS not Suse or Ubuntu, as Suse and Ubuntu both use Postfix as the default.

Alternatives is a program that will allow you to assess and change the mail program or MTA options. To view current links to the program use the following command.

alternatives –display mta

mta – status is manual.

link currently points to /usr/sbin/sendmail.postfix

/usr/sbin/sendmail.sendmail – priority 90

slave mta-pam: /etc/pam.d/smtp.sendmail

slave mta-mailq: /usr/bin/mailq.sendmail

slave mta-newaliases: /usr/bin/newaliases.sendmail

slave mta-rmail: /usr/bin/rmail.sendmail

slave mta-sendmail: /usr/lib/sendmail.sendmail

slave mta-mailqman: /usr/share/man/man1/mailq.sendmail.1.gz

slave mta-newaliasesman: /usr/share/man/man1/newaliases.sendmail.1.gz

slave mta-aliasesman: /usr/share/man/man5/aliases.sendmail.5.gz

slave mta-sendmailman: /usr/share/man/man8/sendmail.sendmail.8.gz

/usr/sbin/sendmail.postfix – priority 30

slave mta-pam: /etc/pam.d/smtp.postfix

slave mta-mailq: /usr/bin/mailq.postfix

slave mta-newaliases: /usr/bin/newaliases.postfix

slave mta-rmail: /usr/bin/rmail.postfix

slave mta-sendmail: /usr/lib/sendmail.postfix

slave mta-mailqman: /usr/share/man/man1/mailq.postfix.1.gz

slave mta-newaliasesman: /usr/share/man/man1/newaliases.postfix.1.gz

slave mta-aliasesman: /usr/share/man/man5/aliases.postfix.5.gz

slave mta-sendmailman: /usr/share/man/man1/sendmail.postfix.1.gz

Current `best’ version is /usr/sbin/sendmail.sendmail.

If you wanted to change from a Sendmail MTA to Postfix MTA use this command:

alternatives –set mta /usr/sbin/sendmail.postfix.

You should not see any output.

To select an alternative from those MTAs available use this command:

alternatives –config mta

You will see this output which will allow you to choose an MTA using a number.

alternatives –config mta

There are 2 programs which provide ‘mta’.

Selection Command

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* 1 /usr/sbin/sendmail.sendmail

+ 2 /usr/sbin/sendmail.postfix

Enter to keep the current selection[+], or type selection number: