how to keep email on android email apps

Dear all.
i have nexus one using FW: 2.3.3. we have hire email in server google with domain but when i config pop mail in my phone, i have problem as when my computer receive email , email in the phone disappear or when i loading new mail, all mail disappear.


Thread starter
Thank you for answer. But can you tell me where option 'Sync deletes with server',please?.
i config POP 3 and use email like gmail