Postfix ships a compatibility layer so that administrators and scripts written for Sendmail keep working unchanged. Which THREE of the following command names does Postfix provide for exactly that purpose?
LPIC-1 Exam 102-500, objective 108. Essential system services medium
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The options
Choose 3.
Correct sendmail
Correct. Postfix installs its own /usr/sbin/sendmail, which accepts the classic mode options such as -bp, -bi, -q and -t and hands the message to the Postfix pickup service.
Correct mailq
Correct. Postfix provides mailq, equivalent to sendmail -bp, so that the familiar queue listing command works.
Correct newaliases
Correct. Postfix provides newaliases, equivalent to sendmail -bi, which rebuilds the indexed alias database from the alias source file.
Not correct postqueue
Wrong for this question. postqueue is genuinely a Postfix command and does list and flush the queue, but it is native Postfix, not part of the Sendmail-compatible set.
Not correct postconf
Wrong. postconf displays and edits Postfix configuration parameters. Sendmail has no such command, so it cannot be part of an emulation layer.
Not correct postfix
Wrong. The postfix command starts, stops, reloads and checks the Postfix system itself. It is native Postfix administration, with no Sendmail counterpart of that name.
Why
The Sendmail emulation layer exists because Sendmail was the de facto interface for decades: local programs call /usr/sbin/sendmail to inject mail, and administrators reach for mailq and newaliases. Postfix and Exim both supply those three names, so a script that submits mail or rebuilds aliases is portable across MTAs. Commands whose names begin with post are native Postfix tools and are not portable.
Where this comes from
- Cited
- manual page sendmail(1)
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 108 and space the ones you get wrong.
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