A constituent may wish to not receive email from your organization. In order to indicate this on their record, you should mark the 'Requests no email' checkbox on the Bio1 tab. We can also mark this checkbox during the Import process.
To mark the 'Requests no email' checkbo when importing, we should be sure to include a column in the import file with the following heading: NoEmail. The value needed in the import file for this column to mark the checkbox is Y, Yes, or True.