Go to the Reports ability, and select Marketing in the sidebar. Click the triangle to the left of this to see your available reports. You'll want to find the "Patient Email Address" report.
Select the provider(s) and office(s) whose patients' email addresses you wish to export, then click the Apply button. You will see a list of patients and their email addresses. Please note, this report will only include patients that have an email address entered. If the email address field is blank, the patient will not be included. At the bottom right corner you will be able to choose from Make List or Export button to start the exporting process. If you click the Make List button please review the Exporting Patient List to Excel documentation.
A new window will appear asking you to specify the location to which you would like the export to be saved. The MacPractice Data Folder is the default save location, but you may want to save it to the desktop to make the file easier to locate. Name the file and change the extension from .txt to .xls to create an Excel file.
When the file is opened in Excel, you will have a list of patient names and email addresses, as appeared on the report.