Yes. Desktop.
I think all email send to desktop at my office(local server)
I try change to imap now
If you have your desktop accessing that mailbox, especially if also via POP3, the following might be happening:
1. Either the messages are removed from the server once they are downloaded by one of the devices, and thus is not visible for the other one, or
2. Even if the the messages downloaded by one device are still on the server, the POP3 server does not consider them as being "new", and does not offer them to your mobile POP3 client (Aquamail).
Whenever you have multiple devices accessing the same account, it is best to use IMAP connection on all the devices (as opposed to POP3).