When you send an email and the number in brackets is less than the selected recipients, it will mean there are either people without email addresses or in the case of parents, it could be that twins/more than one student is causing it. For example, Mrs Jones has two children at the school, Jane and John, so that would be two learners but one email.
When selecting parents, you can select the Undeliverable List to see which parents don’t have emails. This will download a .csv file which can be opened in Excel.
With students, you can see a list when you scroll down on the screen to see missing email addresses.