When a new user is added to my.myob an invitation email is sent to the user, however this email is not cc'd to the company file administrator.
In my experience often the user does not receive this email and there is no way to prove that the my.myob website did in fact send the email.
All invitation emails should be CC'd to the company file administrator a) for security reasons - to keep an eye on unauthorised access b) so they know the email has definitley gone and c) so that the company file administrator can resend the email themselves if it doesn't get there.
Both times it has cost me $$$ with my accountant watching out for the email, contacting MYOB to find out why it hasn't arrived and waiting on the phone. Money MYOB won't refund.