In the Raiser's Edge, there is a checkbox called Requests no email on constituent records that indicate whether or not they want to receive email communication.
Yes, constituents with this checkbox marked on their record are automatically removed from Constituent Queried based email communications mailed from NetCommunity.
Note: Opt outs for Constituent Lists are per Constituent and not per email address. If an email address is shared between constituents within the Raiser's Edge, for example Record A and Record B have the same email address, and if Record A opts out, Record B is still eligible to receive messages.
Note: A Raiser's Edge constituent that is marked Requests No Email is still eligible to receive non-Constituent type emails, for example, if their email address is included on an Imported List, they would receive this email.
Note: This only applies to non-transaction emails. Acknowledgement emails and eReceipts will always be sent out no matter what a user's email preference is.