Install esmtp by entering the following commands in the terminal:
sudo apt update sudo apt install esmtp
Description:
user configurable relay-only MTA
ESMTP is a user configurable relay-only Mail Transfer Agent (MTA) with a sendmail-compatible syntax. It's based on libESMTP supporting the AUTH (including the CRAM-MD5 and NTLM SASL mechanisms) and the StartTLS SMTP extensions. . ESMTP does not receive mail, expand aliases or manage a queue but can deliver mail locally via an MDA. . This package contains the esmtp program.
Homepage: http://esmtp.sourceforge.net/
Version: 1.2-15
Section: universe/mail