Is it possible to add an Outlook Web Addin function to the context menu? As it was possible with the old VSTO Addins:
I only find some examples with tab ribbons, like:
<!--PrimaryCommandSurface==Main Office Ribbon-->
<ExtensionPoint xsi:type="PrimaryCommandSurface">
<CustomTab id="Contoso.Tab1">
<Group id="Contoso.Tab1.Group1">
<Label resid="Contoso.Tab1.GroupLabel" />
<Icon>
<bt:Image size="16" resid="Contoso.TaskpaneButton.Icon" />
<bt:Image size="32" resid="Contoso.TaskpaneButton.Icon" />
<bt:Image size="80" resid="Contoso.TaskpaneButton.Icon" />
</Icon>
<!--Control. It can be of type "Button" or "Menu" -->
<Control xsi:type="Button" id="Contoso.FunctionButton">
<Label resid="Contoso.FunctionButton.Label" />
Outlook Web Add-ins allow customizing the ribbon by adding commands only. Read more about that in the Add-in commands for Outlook article.