Based on our own experience, and from what we heard from other sellers - we'd strongly recommend either Poslaju or Pos Malaysia's registered mail service (Pos Daftar) instead of Pos Ekspress.

Both these services require a signature from the recipient - significantly reducing the chances of lost deliveries. Pos Ekspress is just like a regular mail service, as it drops off the package at the mailbox without handling it over to a person.

As such, there has been cases of buyers not receiving their goods, and sellers end up bearing the cost of the unfulfilled transaction.

Hope this helps!