Gmail has long had the ability to add (and check) other POP3 email accounts, which is nice because it allows you to check/send/receive email from multiple accounts in one place. Of course, with that convenience, the ability to check other POP3 email accounts is not perfect. One of the reasons why is due to the lack of ability to pre-configure a interval to check those accounts. Simply put, they run on Google’s schedule and if you wanted to manually update an account you had to go to Settings, Accounts and Import and then hit the Check mail now link. It was there, but it took a few steps. Now thanks to a new feature in Labs, you can check all of your added POP3 email accounts with a single click. The new Labs feature is called “Refresh POP accounts” and can be enabled by going to Settings -> Labs and then clicking Enable next to the Refresh POP accounts feature. And after that is done, dont forget to hit the Save Changes button at the bottom. Once that is done, just head back to your Inbox and you will now have a “Refresh” link next to your More actions button. Now if we could just get a Labs feature that would just allow us to set time intervals to check those added POP3 accounts.
Read [The Official Gmail Blog]