Once logged-in to your Gmail Account, click the image that says Options located on the upper right hand corner beside your name.
Select Mail Settings from the drop-down.
Open the Accounts and Import Tab.
In the Check mail using POP3 section, click Add POP3 email account.
Enter the full email address of the account you’d like to access, then click Next Step.
Enter your username (your full email address) and password. Verify that the POP Server information uses the following format:
POP Server: mail.b.hostedemail.com
Click Add Account.
Once your account is added, you’ll have the ability to set up this email with a custom From address. This allows you to compose messages in Gmail, but have them appear as sent from your other email account. Click Yes to set-up a custom From address.