If the email addresses you need are already saved in your address book, you can use the native export feature to generate a CSV file, which can be opened in Microsoft Excel. In Outlook Classic (Desktop) Navigate to > Open & Export > Import/Export . Choose Export to a file and click Next . Select Comma Separated Values as the file type. Under your email account, select the Contacts folder. Click Browse to choose a save location and name your file. Click Finish to complete the download. In Outlook on the Web and "New Outlook" Import or export contacts in Outlook using a .csv file

Downloading email addresses from Microsoft Outlook is a straightforward process, whether you are looking to back up your personal contacts or extract a list of addresses from your inbox for marketing and reporting purposes. Depending on your version of Outlook (Classic, New, or Web), the steps vary from using built-in export wizards to manual workarounds. Exporting Saved Contacts to CSV or Excel

Export contacts from classic Outlook to a .csv file * If classic Outlook isn't already open, go to Start and begin typing Outlook. support.microsoft.com