Deleting cleaning emails
iPad and iPhone thought they were mirror images. But even after backups the deletions aren’t syncing?
help
iPhone 7, iOS 13
Mail does not directly synchronise between devices. Instead, Mail messages are synchronised via your Mail Provider's mail server.
If you are using an IMAP mailbox - and both your iPad and iPhone are configured to use IMAP - your devices should be able to keep your view of email synchronised. IMAP keeps all mail on the mail server - keeping a local copy on each mail client.
If instead your devices are configured to use the older POP3 mail protocol, the first device to connect to the incoming Mail server will likely download and delete recently received messages from the server; as such, the other device may not be able to retrieve new messages - as they will have already been deleted from the server. POP3 is not ideal when using multiple devices.