sendmail command not found

Introduction

When you run more command in linux terminal / console, you get the following error message

sendmail: command not found

or when using sudo you get the following error message

sudo: sendmail: command not found

Solutions to sendmail: command not found

How To Fix sendmail: command not found in Ubuntu / Debian / Kali Linux / Raspbian

In Ubuntu sendmail is provided by courier-mta package.

courier-mta is:

The Courier mail transfer agent (MTA) is an integrated mail/groupware server based on open commodity protocols, such as ESMTP, IMAP, POP3, LDAP, TLS, and HTTP. Courier provides ESMTP, IMAP, POP3, webmail, and mailing list services within a single, consistent, framework.

This package provides an ESMTP daemon which uses the Maildir format as native storage format, supports IPv6, implements SMTP extensions for mailing list management and features integrated mail filtering. It can function as an intermediate mail relay, relaying mail between an internal LAN and the Internet, or perform final delivery to mailboxes.

ESMTP over TLS is handled by the regular ESMTP daemon in conjunction with the TLS wrapper.

To fix this problem, we can install more using the command below.

sudo apt-get -y install courier-mta

This command might take some time to finish depending on your machine internet connection.

You can also use apt command to install courier-mta.

sudo apt -y install courier-mta

Or if you have aptitude installed you can use the following command.

sudo aptitude install courier-mta

Summary

In this tutorial we learn how to fix sendmail command not found error in Ubuntu / Debian / Kali Linux or Raspbian distribution.