Microsoft Outlook Not Implemented is a really weird error. I came across this for the first time in Microsoft 365. The individual was unable to send emails. Her emails were stuck in the Outbox.
Now, I tried a few things like repairs and reinstalls and basically they all errored out. I think the solution was to delete the SRS file. My problem was the first time I looked for it I couldn’t find it. I was logged in as a domain user but the domain user had admin rights. It wasn’t until I logged in as the local administrator that I could see the SRS file.
You can find the file here: C:\Users\%username%\AppData\Roaming\Microsoft\Outlook\
As I mentioned earlier Microsoft 365 wouldn’t reinstall without an error each time nor would it complete an online repair. I even manually removed all traces from the computer including the registry. When it did error out I could then go to Programs and Features and then run a local repair and that brought the icons back. It was very confusing.