I have not set up a SMTP host as detailed in the message plugin, without this Moodle relies on the internal PHP mailer, as far as I understand.
With the system current state, any inter user messages are pushed to the relevant end user mail boxes. However forum posts that users are subscribed to and have the correct digest settings are not receiving the forum infomation in an email.
I did tinker with the message email plugin and enter the SMTP details required and also reviewed the CRON jobs and changed those for a period also. However all of which had no impact and messages still had not been issued. I have since reverted any changes i made within the plugin etc.
So I am at a loss on this one. Any pointers or solutions from those who are more enlightened. Note that Moodle is hosted on a server outside of my bricks and mortar. It is run on a server maintained by Siteground, so any cmd line interaction might be difficult.