Outlook 2016 and QuickBooks Pro 2015 not working anymore, why?
Outlook 2016 is not compatible with QuickBooks Pro 2015. Outlook 2016 is compatible with QuickBooks 2016 and the earlier versions.
See this will help to switch to Webmail:
- Go to Edit, then choose Preferences.
- Select Send Forms.
- Go to the My Preferences tab, then choose Web Mail.
- Click Add, fill out the Add Email Info screen and click OK.
- Click OK.
Also, read this article: Set up your email service in QuickBooks Desktop