Need better mail synchronization on mobile devices
Messages deleted on one mobile device (iPhone) still show up as new mail on another device (iPad) and visa versa. It’s annoying to have to delete 100 or so messages twice!
1st
ranked

Make sure you’re using an IMAP connection on your mobile device. You can also remove and re-add the account to the mobile app in order to resync things.
Thank you!
Mail Support