Docker mailserver

Create an account using setup.sh

https://docker-mailserver.github.io/docker-mailserver/latest/config/user-management/accounts/

TLS certificates

Certificates from Caddy | https://docker-mailserver.github.io/docker-mailserver/latest/config/security/ssl/#caddy | https://docker-mailserver.github.io/docker-mailserver/latest/config/security/ssl/#bring-your-own-certificates

docker-mailserver doesn't support EC certificates, that's why I forced RSA4096 certs for the mail.aosus.org domain in https://github.com/aosus/hyper-aosus/commit/1a3edc1cacab10f5b3c6d8a3034a49c6a9d9b0c7

Setup DKIM

./setup.sh -c mailserver config dkim keysize 4096 domain discourse.aosus.org

cat /tmp/docker-mailserver/opendkim/keys/discourse.aosus.org/mail.txt make it one line and remove all quotes and spaces, then added to cloudflare as mail._domainkey.discourse.aosus.org

setup dmarc

https://docker-mailserver.github.io/docker-mailserver/latest/config/best-practices/dmarc/ replace example with discourse.aosus.org

copy SPF record and add it Cloudflare

https://docker-mailserver.github.io/docker-mailserver/latest/config/best-practices/spf/

Enable POP3, and open 995 port

POP3 is needed for email replies and bounce detection for discourse. https://docker-mailserver.github.io/docker-mailserver/latest/config/pop3/