A lot of information sent to parents is through the management system of the school, sport or activity.
These are generally sent from generic email addresses, some examples of things my family receives are: [email protected] and [email protected]
Now, if you add these addresses in a Contact that is in a Channel in Cubby, we will pull emails from them. The problem is when two of your kids are both using the same service provider.
Check the Reply-To Field
Nearly all school/sports/activity software has the sender of the email as a "Reply-To" on the message. This is so that if you reply to the message it goes to the person who sent it and not the general email address.
Good news! Cubby filters not only the sender address, but also this Reply-To field.
In this case you would add the email address in the Contact to be what is in the Reply To field and not the From field