Le serveur pris pour l'exemple est un exchange.
dnf install sendmail
dnf install postfix
dnf install cyrus-sasl
dnf install cyrus-sasl-plain
nano /etc/postfix/main.cf
myhostname = maarch.org
relayhost = [mon.serveur.smtp]:587
smtpd_sasl_type = cyrus
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
sender_canonical_classes = envelope_sender, header_sender
sender_canonical_maps = regexp:/etc/postfix/sender_canonical_maps
smtp_header_checks = regexp:/etc/postfix/header_check
nano /etc/postfix/sasl_passwd
[mon.serveur.smtp]:587 No-reply.courrier@maarch.org:thePassword
nano /etc/postfix/sender_canonical_maps
/.+/ No-reply.courrier@maarch.org
nano /etc/postfix/header_check
/From:.*/ REPLACE From: No-reply.courrier@maarch.org
nano /etc/mailname
maarch.org
chown root:postfix /etc/postfix/sasl_passwd
chmod 640 /etc/postfix/sasl_passwd
postmap /etc/postfix/sasl_passwd
sendmail -v support@maarch.fr
systemctl start postfix
systemctl enable postfix