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LFCS · Question #43

What is true regarding the command sendmail?

The correct answer is B. All MTAs, including Postfix and Exim, provide a sendmail command. Many different Mail Transfer Agents (MTAs), such as Postfix and Exim, provide a compatibility layer that includes a sendmail command. This ensures that applications expecting the traditional Sendmail interface can still submit mail regardless of the underlying MTA.

Submitted by krish.m· Apr 18, 2026Operation of Running Systems

Question

What is true regarding the command sendmail?

Options

  • AWith any MTA, the sendmail command must be run periodically by the cron daemon.
  • BAll MTAs, including Postfix and Exim, provide a sendmail command.
  • CThe sendmail command prints the MTAs queue history of which mails have been sent
  • DIt is only available when the sendmail MTA is installed.

How the community answered

(17 responses)
  • A
    6% (1)
  • B
    88% (15)
  • C
    6% (1)

Why each option

Many different Mail Transfer Agents (MTAs), such as Postfix and Exim, provide a compatibility layer that includes a `sendmail` command. This ensures that applications expecting the traditional Sendmail interface can still submit mail regardless of the underlying MTA.

AWith any MTA, the sendmail command must be run periodically by the cron daemon.

The `sendmail` command is typically used for submitting mail, not for periodic cron tasks to manage the queue; the MTA's daemon handles queue processing.

BAll MTAs, including Postfix and Exim, provide a sendmail command.Correct

Most modern MTAs like Postfix and Exim provide a `sendmail` command (often as a symbolic link or wrapper script) that mimics the original Sendmail program's interface, allowing applications to submit mail without needing to know the specific MTA installed.

CThe sendmail command prints the MTAs queue history of which mails have been sent

The `sendmail` command, when used with parameters like `-bp` (or via `mailq`), can list the current contents of the mail queue, but it does not print a history of sent mails.

DIt is only available when the sendmail MTA is installed.

This is incorrect because other MTAs commonly provide a compatible `sendmail` command for interoperability, even if the actual Sendmail MTA is not installed.

Concept tested: MTA sendmail command compatibility

Source: https://www.postfix.org/sendmail.8.html

Topics

#sendmail command#MTA#email systems#Postfix

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