Cseries :: C3-01 Mail Out Of Memory - Restart Application

My Nokia C3-01 RM-640 has V 07.15 firmware and version 2.2.45 email software. This is the latest software according to Nokia Suite. I like the phone very much but there is a serious problem with the operation of the email software. Almost every time I try and open an email I get a message "Mail out of memory. Restart application". Occasionally I get the "java/lang" memory error that others have referred to. This renders the email function virtually useless. I am using the phone's standard built in email program. I delete all old emails. I have no games or apps installed on the phone and the phone memory (as opposed to the card memory) is showing 20% free.