The email sent from the apps do not contain the DKIM signatures eg. wordpress have delivery problem with the email sent to the users because of this.
Doesn’t the rmilter by default signs every email sent ? If not how can be php apps configured to sign the emails ?
Have you properly set your DNS records for DomainKeys for your mail server domain name? Have a look at the DNS configurations of the domain in the YunoHost admin panel, it should show you the records to be set in your DNS zone file.
Sorry for the late reply.
Yes I have correct DNS recored for the domain keys , I have cross checked it. Its related to this issue https://github.com/YunoHost-Apps/wordpress_ynh/issues/23