You can make e-mail for two different addresses go to the same POP mailbox. Just create a normal POP mailbox for one of the addresses and a forwarding alias for the other address.
For example, to deliver mail for sales@example.com and info@example.com into the same POP mailbox, you could create a POP mailbox for sales@example.com, plus a forwarding alias for info@example.com that forwards to sales@example.com.
(You could do it the other way around if you wanted, making info@example.com be the POP mailbox and sales@example.com be the forwarding alias. It doesn't matter which is which, because the end result is the same: messages sent to either address end up in a single POP mailbox that you read, and only you will know which is the "real" one.)