Extra warning about POP

When you use POP, mail messages are downloaded from the inbox and stored in the app. With Exchange or IMAP, messages and folders on the server side are temporarily downloaded and displayed, and the operations in the mail application are reflected on the server.

If you have set your POP configuration to delete messages on the server after fetching them, the old mail has been deleted from the server and you cannot read them using Exchange. In this case, you may lose old messages downloaded to the app if you delete your POP account. Please make sure to back up your messages before deleting your POP account.

For email apps that can register multiple accounts with the same email address and do not have a method for backing up emails (such as iOS default Mail app), do not delete your POP account, but add an Exchange account. On the POP account side, please set not to delete messages from the server when fetching messages. The same email will be shown by both accounts. Please note that depending on your POP settings, deleting a message on the POP account may delete the same message on the server, and also remove it from your Exchange account.