why can't I see mail in my subfolders following recent upgrade on iPhone 12

Hi MaxRubyMidge,

Thank you for trying those steps. Is this happening with an iCloud Mail account or a third-party account? You mentioned that the folders are available on your iPad and your Mac, do you also see them available in the webmail?

Has the mail account been removed and added back to your device? This steps can help resync your Mailboxes and folders.

1. Go to Settings > Mail > Accounts
2. Tap on the email account
3. Tap on Turn off Mail

Add and remove email accounts on iPhone

To add the account back:

1. Go to Settings > Mail > Accounts > Add Account
2. Tap on Email service
3. Enter your credentials

If this continues after following those steps, you may want to reach out to Apple Support for further assistance. Depending on your region, you may be able to reach them here: Get Support.

Hope that helps!

Hello MaxRubyMidge,

Since you aren't seeing your email in certain folders, let's restart your iPhone using the steps below:

1. Press and hold either volume button and the side button until the power-off slider appears.

2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.

3. To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo.

You can also find those steps in this resource: Restart your iPhone A restart can sometimes help address odd behaviors.

Should that still persist, do you have multiple email accounts set up on your iPhone? If so, is this happening with all your email accounts or only certain ones?

Do you have the those same accounts set up on your iPad? If so, are those particular folders also empty on your iPad?

Let us know, and we'll keep moving forward based on those details.