Documenso ⇒ Postfix local (port 25) ⇒ Resend SMTP (port 587) = Internet

Lien : https://resend.com/

• générer une clé d'API

apt update
apt install postfix mailutils libsasl2-modules

• Créer le fichier /etc/postfix/sasl_passwd

[smtp.resend.com]:587 apikey:re_123456789abcdef

postmap /etc/postfix/sasl_passwd
chmod 600 /etc/postfix/sasl_passwd*

• copier les modules SASL dans le CHROOT

mkdir -p /var/spool/postfix/usr/lib/x86_64-linux-gnu/sasl2/
cp -a /usr/lib/x86_64-linux-gnu/sasl2/* /var/spool/postfix/usr/lib/x86_64-linux-gnu/sasl2/

• éditer /etc/postfix/main.cf :

nano /etc/postfix/main.cf

• Ajoute / remplace :

relayhost = [smtp.resend.com]:587

smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous

smtp_use_tls = yes
smtp_tls_security_level = encrypt
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

inet_interfaces = all
inet_protocols = ipv4

systemctl restart postfix