feat: self-hosted postfix

docker/postfix/opendkim.conf

@@ -0,0 +1,30 @@
+# OpenDKIM configuration for email signing
+
+# log to syslog
+Syslog                  yes
+SyslogSuccess           yes
+LogWhy                  yes
+
+# required for verification
+Canonicalization        relaxed/simple
+
+# sign mode (s=sign, v=verify)
+Mode                    sv
+
+# sign subdomains
+SubDomains              no
+
+# key configuration (will be set by entrypoint)
+KeyTable                /etc/opendkim/KeyTable
+SigningTable            refile:/etc/opendkim/SigningTable
+ExternalIgnoreList      refile:/etc/opendkim/TrustedHosts
+InternalHosts           refile:/etc/opendkim/TrustedHosts
+
+# socket for postfix connection
+Socket                  inet:8891@localhost
+
+# user
+UserID                  opendkim
+
+# permissions
+RequireSafeKeys         false