Expiration Reminder by default will send an individual email notification for each expiration. This can be changed if needed to instead of sending individual notifications to instead group them into one email summary that includes all notifications.
This is done by changing the delivery type at the contact level. The delivery type manages how notifications are delivered to the contact. When adding a new contact this defaults to individual email and notifications. To change it to be grouped, change the delivery type to Digest - Grouped Emails.
How it looks like
This is how an email digest with grouped notifications looks like:
Changing the delivery type of a contact to digest
Look for the contact to be changed by clicking on Contacts on the top menu.
Look for the contact and click on the it. Then click on Edit Contact.
On the contact edit screen, change the Delivery Type field to Digest - Grouped Emails.
Digest are scheduled to be sent on a specific time:
Daily
Weekly
Monthly
Depending on the schedule, the system will group all notifications for that period and send them in a single email.