Ubuntu Server 18.04でサーバー構築 メールサーバー導入
1.Postfix : Installation / Configuration Postfix is a software developed as an MTA (Mail Transport Agent) to replace Sendmail, and is a mail server with features such as high compatibility with Sendmail, security, easy maintenance, and speed. Also, since Postfix only functions as an SMTP server for sending mails, you will need to install a POP server for receiving mails separately as described later. 1.1 Install Install Postfix and build an SMTP server. 25/TCP is used for SMTP.