{$WEBMAIL_SUBDOMAIN}.{$DOMAIN_NAME} { reverse_proxy email_frontend:3000 } {$MAIL_SUBDOMAIN}.{$DOMAIN_NAME} { reverse_proxy email_backend:8080 header { Access-Control-Allow-Origin "https://{$WEBMAIL_SUBDOMAIN}.{$DOMAIN_NAME}" Access-Control-Allow-Credentials "true" Access-Control-Allow-Methods "GET, POST, OPTIONS, PUT, DELETE" Access-Control-Allow-Headers "Authorization, Content-Type, X-JMAP-Prefix, X-JMAP-Framework" } @options method OPTIONS respond @options 204 }