To change "Alerts" you receive from saved searches click on "saved searches" in the top right profile of the site or use this link while logged in. https://www.zumper.com/alerts
Then you will be able to see all your searches, where you can select "customize" to open up more options.
To unsubscribe from alerts, select "delete saved search" or uncheck the "Email Notifications" box.
You can also unsubscribe from Zumper alerts directly from the email. Simply scroll to the bottom of the message and select the "manage notifications" link. Select the unsubscribe from all notifications option and save your updates.
This will prevent you from receiving any further correspondence on Zumper alert emails for that particular search. If you have alerts selected to multiple searches, you will need to unsubscribe from each one.