Postfix docker
https://hub.docker.com/r/boky/postfix/
https://github.com/jeremybusk/docker-postfix
https://help.ubuntu.com/community/PostfixCompleteVirtualMailSystemHowto
https://wiki.debian.org/opendkim
https://www.linuxbabe.com/mail-server/setting-up-dkim-and-spf
Alternatives
https://github.com/mail-in-a-box/mailinabox
https://github.com/eldada/postfix-relay-kubernetes
https://github.com/catatnight/docker-postfix
https://github.com/juanluisbaptiste/docker-postfix best?
https://github.com/jessfraz/dockerfiles/tree/master/postfix
https://github.com/noteed/docker-postfix/blob/master/Dockerfile
https://github.com/alterrebe/docker-mail-relay
https://upcloud.com/resources/tutorials/secure-postfix-using-lets-encrypt
https://ubuntu.com/server/docs/mail-postfix#:~:text=SMTP%20Authentication
https://help.ubuntu.com/community/PostfixDovecotSASL
https://wiki.debian.org/PostfixAndSASL
https://github.com/humpedli/docker-postfix-dovecot
https://doc.dovecot.org/configuration_manual/authentication/password_schemes/
https://doc.dovecot.org/configuration_manual/howto/postfix_and_dovecot_sasl/
https://neoserver.site/help/step-step-installation-instructions-postfix-and-dovecot-ubuntu
https://www.linode.com/docs/guides/postfix-smtp-debian7/
Short
passwd encryption
- https://superuser.com/questions/1395665/is-there-a-way-to-encrypt-mail-password-when-configuring-mail-notifications-usin
- https://cyrus-sasl.andrew.cmu.narkive.com/nkR0CFqv/etc-sasldb2-and-plaintext-passwords
DKIM
- https://tecadmin.net/setup-dkim-with-postfix-on-ubuntu-debian/
- https://ubuntu.tutorials24x7.com/blog/set-up-dkim-domainkeys-with-postfix-on-ubuntu-20-04-lts
- https://github.com/dodancs/DKIM-auto-signing
- https://github.com/captbrando/dkimrotator/blob/master/dkimrotate.sh