Recently I discovered Mailcow, and looks so good, but I have a problem with some weird configuration I am trying.
I have a domain using Google as mail server (that old free accounts). Now I want to use my Mailcow at home to send emails with same domain, but keeping “main” mail at Google, so MX are still pointing at Google.
I added the domain to Mailcow and local network (192.168.1.0/24) to “mynetworks” on main.cf. On “smtpd_relay_restrictions” added “permit_mynetworks”.
When I send a mail from some server on local network, with no authentication using telnet, I got “5.7.1 This message does not meet our delivery requirements”.
I didn’t created any mailbox on Mailcow, as don’t want to create a bunch of mailboxes for any service/server (NAS, docker server, etc).
Is it possible to configure Mailcow to send from any email address on local network for a domain with no mailboxes?
Thank you in advance.