feat: add mail/v2

mail/v2/doc

@@ -0,0 +1,26 @@
+# create password
+doveadm pw -s MD5-CRYPT -p admin | sed 's/{MD5-CRYPT}//'
+
+chown -R mail:mail /var/lib/vmail/
+chown -R postfix /var/lib/postfix/
+
+
+
+spamassassin ? rspamd \
+
+# start apps
+/ # opendkim
+/ # dovecot
+/ # syslogd
+/ # postfix start
+
+
+# useful documents
+https://www.linode.com/docs/guides/configure-spf-and-dkim-in-postfix-on-debian-9/
+https://github.com/postfixadmin/postfixadmin/blob/master/DOCUMENTS/Postfix-Dovecot-Postgresql-Example.md
+https://doc.dovecot.org/configuration_manual/howto/postfix_and_dovecot_sasl/
+https://wiki.archlinux.org/title/Virtual_user_mail_system_with_Postfix,_Dovecot_and_Roundcube
+
+# do some checking
+postmap -q esin.io proxy:pgsql:/etc/postfix/pgsql/virtual_alias_maps.cf
+postmap -q hi@esin.io proxy:pgsql:/etc/postfix/pgsql/virtual_mailbox_maps.cf