Inbox Follow Up Menu doesn't display all options

JoCoastal Hello, I haven't heard that one before and I've encountered many issues in the Outlook client! (I assume your using that). Even though you can troubleshoot specific problems, my experience has taught me that either a new .ost file or a new Outlook profile will solve almost every client related problem more quickly.

But before that you could try an "Office repair" to see if it restores the feature you're missing.

https://support.office.com/en-us/article/repair-an-office-application-7821d4b6-7c1d-4205-aa0e-a6b40c5bb88b?ui=en-US&rs=en-US&ad=US

Create an Outlook profile

https://support.office.com/en-us/article/create-an-outlook-profile-f544c1ba-3352-4b3b-be0b-8d42a540459d?ui=en-US&rs=en-US&ad=US 

Introduction to Outlook Data Files (.pst and .ost)

https://support.office.com/en-us/article/introduction-to-outlook-data-files-pst-and-ost-222eaf92-a995-45d9-bde2-f331f60e2790