Email skipping to next unread while reading a different email

Hi Kathryn Lampi,

Thanks for posting in Apple Support Communities.

We understand while reading an email, the following email opens without being prompted. To address this behavior, remove and add the affected email account back. If you have an IMAP account, all your emails are saved to the ESP's server and will restore when you add the account back to your iPhone.

Log out of or remove email accounts

1. Go to Settings  > Mail > Accounts.

2. Tap the email account you want to remove, then do one of the following:

* If you’re removing an iCloud email account: Tap iCloud, tap iCloud Mail, then turn off “Use on this iPhone.”

* If you’re removing another email account: Turn off Mail.

* Note: To remove the email account from all apps on your iPhone, tap Delete Account.

Add email accounts

The first time you open the Mail app on your iPhone, you may be asked to set up an email account—just follow the onscreen instructions.

To add additional email accounts, do the following:

1. Go to Settings  > Mail > Accounts > Add Account.

2. Do one of the following:

* Tap an email service—for example, iCloud or Microsoft Exchange—then enter your email account information.

* Tap Other, tap Add Mail Account, then enter your email account information.

Add and remove email accounts on iPhone - Apple Support

Regards.