postfix

• /etc/postfix/main.cf

		myhostname = FDQN
		mydomain = FDQN
		 #inet_protocols = all
		inet_protocols = ipv4
		#home_mailbox = Maildir/
		home_mailbox = Maildir/
		smtpd_sasl_auth_enable = yes
		broken_sasl_auth_clients = yes
                smtpd_recipient_restrictions = permit_sasl_authenticated, reject_unauth_destination
                inet_interfaces = all

 #### by lapidem
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_sasl_authenticated, reject_unauth_destination

apt -y install mailutils