Yes, if a patron would like to opt out of receiving welcome, courtesy, overdue, and account expiry emails they can do so through  Preferences -> Notifications in My Account in the public catalogue.

Information on how to opt out can be found here. This documentation is available to your patrons via the Help link in footer of your public catalogue.

Library staff can also un-check the box “Receive Overdue and Courtesy Emails” in the Edit screen of patron’s account in the staff client.