Hi Raluca,
I can't understand your customer. Why should he pay more attention to a notification than an information email? He could add a separate folder to his Outlook mailbox that is just for email notifications.
With a rule in Outlook, he can simply redirect all emails automatically to this folder and thus have his "important" information emails separated from the other emails.
When someone is given a task to work on, they simply have to work on the task. The medium through which he receives the information does not matter, the task must still be completed. At some point the customer will says that he is getting so many notifications that he no longer pays any attention to them... and then?
In my opinion the problem here is poor self-organization, which you should now solve with a WEBCON custoimizing.
This is a difficult task for you.
Maybe you can convince the customer of the Outlook solution. WEBCON is a great program, but it can't change a person's personal attitude.
Good luck that you find a satisfying solution that isn't too complicated :)