add mail account

docker exec -ti mailserver setup email add info@example.com

add alias

# add alias as it is popular to do this
docker exec -ti mailserver setup alias add postmaster@example.com admin@example.com

# add alias for matrix.spfbl.net delist (sends delist email to mail.example.com)
docker exec -ti mailserver setup alias add postmaster@mail.example.com admin@example.com

get list of emails

docker exec -ti mailserver setup email list

add dkim domain

docker exec -it mailserver setup config dkim domain example.com