If you have feedback for TechNet Support, much the same way, by opening the HTML in Word then copy/pasting. If you have feedback for TechNet Support, can reproduce this issue and I guess this issue has something to do with the new Attach File menu button in Outlook 2016. Mark the reply as an answer if you find it is helpful. Method 2: Open the HTML file using Word (right-click on the HTML file and select Open With.), press Ctrl + A to copy all the contect in the Word document and then paste the content to Outlook. Note: It's reported that this method doesn't work on Windows 7 OS, but it's worth a try.
Now, when we insert a html file, use the Attach File button on the QAT, you will see the To do this, click New Email button to open a new email message, click File > Options > Quick Access Toolbar. Method 1: Add the Attach File icon to the Quick Access Toolbar. We can try the following method to work around this issue: I can reproduce this issue and I guess this issue has something to do with the new Attach File menu button in Outlook 2016.
