Sometimes, add-ins do not fully load into Outlook, preventing them from being visible (or from working properly). You can tell this is the problem because when you look at the list of add-ins you might see something similar to this:
To fix this, follow these instructions to see if they help:
1) In Outlook go to File...Options...Add-Ins and look for the "Sperry Software Engine" entry:
Note that the Location (path) and the name of the Sperry Software Engine could change, depending on the settings used when installed.
2) At the bottom of the window, click on the Manage [COM Add-ins] Go button:
Take note of the entire Location, you'll need this in just a bit.
3) Highlight the Sperry Software Outlook Add-Ins Engine, then click Remove (on the right)
You may run into an error message here that says "This add-in is installed for all users on this computer and can only be connected or disconnected by an administrator." If this is the case, exit out of Outlook altogether, and reinstall per user instead of per machine. Note that you may have to contact your IT administrator if you are not allowed to install/uninstall programs. After that, try these instructions again, assuming the problem is still present.
4) Exit Outlook
Make sure it is completely finished by checking Task Manager
5) Restart Outlook, and go back to File...Options...Add-Ins, then click on the Manage [COM Add-Ins] Go button again.
6) Now click on Add...and navigate to the previous Location and select the SperryShim-HKCU.dll (or possibly the SperryShim-HKLM.dll) file.
Note that the usual location for this file is the installation folder, which is C:\Program Files\Common Files\Sperry Software (or C:\Program Files (X86)\Common Files\Sperry Software if you are on a 64-bit machine and have 32-bit Outlook).
7) Exit Outlook one more time.
Again, make sure Outlook is completely finished.
8) Restart Outlook
The add-in should now be present in the toolbar.
If not, there is one other option, to reinstall as an Administrator and choose the per machine option. To do this, follow these instructions:
1) Exit Outlook
2) Uninstall the add-in via Control Panel...Programs and Features...Uninstall a Program
3) Download then run the Uninstall AddIns tool
4) Login as an Administrator (assuming you are not already one)
5) Right click on the add-ins' setup EXE and choose "Run As Administrator"
6) During installation choose per machine and not per user
7) Restart Outlook and verify that the add-in is present (note: you may have to right click on the Outlook.exe program and select "Run As Administrator")
8) Logout and login again as the user
9) Start Outlook
The add-in should now be visible. If not, please contact firstname.lastname@example.org for further help.