Cannot permanently delete emails from devices

Hello Scottingtonb,

Welcome to Apple Support Communities!

We want to help get the emails to be fully deleted when you delete them.

Use these steps to delete the emails:

"Delete multiple emails at once 

1. Open Mail and go to your Inbox.
2. Tap Edit in the upper-right corner, then individually select the emails that you want to delete, or tap Select All. To select multiple emails quickly, swipe down through the checkboxes.
3. Tap Trash or Archive. If you only see Archive, touch and hold Archive to see other options like Trash Selected Messages."

Make sure they are being sent to the trash and not archived. This Apple Support page has the full details: Delete emails on your iPhone or iPad - Apple Support

You'll want to reach out to Yahoo support if the emails continue to not delete when expected from multiple devices, as it would indicate an account issue not a device issue.

We hope this helps to isolate and resolve the issue with the emails not deleting.

Cheers!

Howdy Scottingtonb,

We're glad this has been cleared up for you, and we appreciate the update.

Since you mentioned the MacBook Pro was running a little slower, we'll include a link below for assistance with slow performance. This may be expected depending on the amount of available storage, macOS version, and other contributing factors, so this resource can help if you'd like to review it.

If your Mac runs slowly - Apple Support

Have a great day!