Undelete of emails

If you actually have any type of data backup ( either from an iCloud backup or device backup from a full Mac or Windows PC ) from a few days, ago, then recovery of these emails maybe possible.

If no actual backup, then maybe no recovery of these deleted emails.

Be advised, if using a third party email service with an iMAP account, deleted email may still reside on the email service servers.

You made need to use a Web browser and go the actusl email service Website, login into your acount on the Website and look through all of your emails there to see if these emails still exist on the actual email service account.

If they do you could re-email/forward these missing emails back to yourself, using your email address.

Good Luck!

If iCloud backup was, also, actvated for the Mail app, you shoukd be able to restore a previous iCloud backup.

Tap the link below.

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Good Luck!

Just ckeck in the Settings app, under your Apple ID at the top.

Tap iCloud and check to see which apps are using iCloud.

If Mail is toggled on using iCloud ( blue dot or blue bar next to app name to indicate backup ), then you should be good to try an iCloud restore of a previous backup.

I am making NO guarantee that these emails will be retrievable, or not.

Good Luck to You!