I deleted the mail app, then reinstalled by going to the App Store and searching for “Mail”, it was second from top. After reinstalling, I went into Settings > Mail > Accounts, and for each of the accounts (I have 10!) I had to go in and flip the switch to “on” for Mail. After that I went into the Mail app, it started downloading all my email again and now I only have VIP in the VIP folder now.
Note: to re-enable iCloud email it’s slightly different… when you tap on it from the list of accounts, it takes you to the Apple ID screen. From there you go to iCloud > iCloud Mail > Use on this iPhone/iPad.
Also: prior to this I tried updating to the latest iOS and I tried removing just my Gmail account as others had suggested. Neither of those fixed the issue for me. Doing it this way reinstalling the mail app kept me from having to set up all my accounts from scratch. You just have to flip the switches back to the on position in the settings page and you’re set!