I set up a mailcow docker. It works very well !
Yet I have an issue :
This server is used to send mail on behalf of my customers (and to manage my own mails). One of my customers sends a lots of mails, so we made the decision to relay the mails sent with a from like “email@example.com” to one of their mail servers.
I did so on my previous postfix mail server by setting in main.cf these lines :
sender_dependent_relayhost_maps = hash:/etc/postfix/relay_maps
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
and by making a postmap of these two files.
I tried to set it up in mailcow using the documentation based on the Relayhosts section. But when I do so, if someone from this customer company send me an email (from “firstname.lastname@example.org”), this email is not delivered to me… with my previous postfix setting it was not the case : only outgoing mails where relayed to the host not the incoming ones.
I could try to do some some docker-compose postconf but I absolutely do not know how to create the 2 files /etc/postfix/relay_maps and /etc/postfix/sasl_passwd and postmap them.
Would someone help me either from the Mailcow UI, or with some docker-compose instructions ?