POP e-mail fetching is a great feature of Gmail to retrieve messages from your other emails accounts via POP and display them in your inbox alongside the emails that come directly to your Gmail account.
Anyone who has been channeling emails from various addresses to one master Gmail address, knows that Gmail uses a timing algorithm to retrieve messages from POP accounts. The problem, however is the time lag. Often you would want to instantly check whether the email you were waiting for has arrived or not.
Quickly Check If a New Email Has Arrived or Not :
To check or retrieve emails at any desired time, head to your email settings and under Labs, enable the “Refresh POP Accounts” option. Then save changes.