Why is the MailMerge365 icon not showing up in Outlook?

When you compose a new email the MailMerge365 icon should appear either in the menu bar (Desktop Outlook) or in the Add-In bar (Web Outlook). If it does not please reinstall the plugin as described in out tutorial. 

Things to note:

• The plugin must be installed for each account you are using in Outlook seperately.
• The icon only appears when you are in composer mode (creating a new mail).
• If you are on Mac and using "New Outlook" (currently in Beta therefore not widespread yet) there are some extra issues:
  • Enable "Optional Connected Experiences" in your privacy settings, which is required for Add-Ins to work
    • 
  • You may have to reinstall the plugin in this new mode.
  • The icon may be hidden behind the "3 dot" menu at the top of the window (instead of as in the older version at the bottom).