set up mail server with docker mail server

 docker mail server :

https://github.com/docker-mailserver/docker-mailserver

guide :

https://betterprogramming.pub/how-to-set-up-a-mailserver-within-a-docker-swarm-e6e9192200c4

Most important thing before starting is to set up mail record for desired domain:

https://linuxize.com/post/set-up-an-email-server-with-postfixadmin/

• A record, to point your system’s FQDN (hostname) to your mail server IPv4 address.

mail.linuxize.com. 3600 IN A   23.45.67.89

The FQDN consists of two parts, the hostname and the domain name.

• MX record, to specify which mail server is responsible for accepting email messages on behalf of a recipient’s domain. In our case we want all emails sent to @linuxize.com email addresses to be accepted by the mail.linuxize.com mail server.

linuxize.com.      3600 IN MX  0 mail.linuxize.com.

• SPF record, which is used to verify which mail servers are approved to send email on behalf of a given domain. In the example below we are approving the domain mail servers (mx) and if the SPF check fails, the result will be a soft failure (~all):

linuxize.com.      3600 IN TXT "v=spf1 mx ~all"