predicted mailbox issues

I have a macbook pro (with touch bar), running macOS High Sierra. For the last couple months I have been unable to get the predicted mailbox function in the Mail application to work. When I first got the computer, I had no problems. The only difference for the last couple months is I've been using a gmail account as opposed to yahoo previously. Also I upgraded from Sierra to High Sierra. I tried rebuilding the mailbox, checking the imap settings, deleting the gmail account and then adding it again. Any one having similar problems or found a solution? I've been searching the forums and can't seem to find any answers.