I have MS outlook on my Dell laptop for my gmail account. My inbox sometimes refuses to update. I highly suspect that I get so many spam messages that it breaks the process. When this happens, In order to see my inbox I have to go to the web version of gmail, and see my messages there. I clean out the messages. Restart outlook on my laptop. Reboot the entire laptop. And then eventually it will work again. It happens pretty much every day.
I read earlier threads on this. I orginally had 2 outlook accounts, and I deleted one I didn't really use to see if that helped, and it did not. Other suggestions were to turn cache on or off, but I didn't have the options they described, available.
On my phone it may or may not match what my laptop is doing.
The only thing I can think of to do, is to create a whole new email and start using that. I really don't want to, but that is the plan, whenever I can get around to it.
Any other ideas? Also, I came across something on the web about fixing outlook problems and it involved downloading an app, which I did, but have not used it. The app looks like something service techs would use, and it might work, but I don't have documentation on how to use it.