Office add-in is not activated on Outlook if open

Question

My add-in has a MessageComposeCommandSurface ExtensionPoint that adds a button to the ribbon when the user is composing a message and MessageReadCommandSurface for the read mode.

I expected the button to always be enabled when it is visible (e.g. when the user is composing a new message or replying to an existing one).

Works perfectly, but my add-in is greyed out/disabled when opening a template (save a message as a template and open .msg file with outlook).

1. Add-in is greyed out if .msg was saved from composing mode.
2. Add-in is disabled if.msg was saved from read mode.

Does anyone know the why an add-in ribbon button is greyed out/disabled when opening a .msg template (open in a read mode)? At the same time, add-in is available when reply/forward, etc. for just opened .msg template.

Answer 1

Add-ins are grayed out/disabled because they are not supported in .msg files nor in message templates.

Answer 2

Solution: Also you can move *.msg files to folders. Click on the Tab File -> Move to Folder ->Copy to Folder choose particular folder. When msg was moved to folder go to your outlook and add-in is available. I hope that was useful for you.

Answer 3

Add-in is enabled for Outlook Template (*.OFT), so need to open and save the message as outlook template with .oft format.