Note 2: Using Gmail POP3 on mobile or multiple devices ?
If you’re accessing your Gmail using POP3 from multiple clients, Gmail’s “recent mode” makes sure that all messages are made available to each client, rather than only to the first client to access new mail. Recent mode fetches the last 30 days of mail, regardless of whether it’s been sent to another POP client already. To do this, replace ‘username@gmail.com’ in your POP client settings with ‘recent:username@gmail.com’.