Consider adapting the Microsoft 365 add in to be used for all correspondence on the users desktop, not cloud, but also avoiding the programs word editor. Currently mass emails must go through a  process of creating a distribution list, starting an email merge, drafting an email and sending your message. Perhaps you could use some of the process in the Junxure add in to allow for all to be done in a users desktop version instead of cloud. This would give the user the flexibility of sending to both a primary and secondary recipient, current fonts, utilizing templates more efficiently and including attachments in both emails and templates which currently is not an option.