OWA web parts in SharePoint 2013
When I tried finding the OWA web parts in the SharePoint 2013 OOTB web parts, I couldn't find the web parts and “Outlook Web App” category is also not available. I was thinking it is deprecated or not available in SharePoint
After searching, I found the following solution.
Steps to add Outlook web parts
1. Go to Web part Gallery.2. On Web part Gallery page, Click Files-> New Document -> New in the ribbon.
3. On New web part page (NewDWp.aspx), look for Microsoft.SharePoint.Portal.WebControls.OWA, select the web parts related to the outlook as shown below and populate gallery.
4. Now, under Miscellaneous Category, you will see the web parts related to Outlook.
Hope this helps you!