Hello @RSWarehousing, thanks for explaining the issue you're experiencing. Here are the steps that should help:

1. From the Edit menu, choose Preferences, and select Send Forms.
2. Under My Preferences tab, tick the Web mail radio button and click Add.
3. Fill out the Add Email Info screen and click OK.
4. Click OK to save the Preference.

Microsoft Outlook uses outlook.office365.com for the Server and 587 for the port (SSL enabled). You can also check out this article for more information: Set up your email service in QuickBooks Desktop.

Please let me know if these steps work for you! We definitely want the emails to be correct in your invoices for your customers. :)