Email/Callout notifications are not sent to client, why?

[Leo]

Question or Problem Statement:
One our client complains she has never got the monthly generated invoice by email, why?

[Leo · Accepted solution]

Solution:
a).Review what 'Communication Profile' that customer account ties to. For example, AAA.
b).Review the 'Communication Profile' AAA, locate the corresponding event. For example, "Invoice Posted | Invoice Posted within a Bill Run of Auto-Post", to verify if it has been turned on.