1. Open the Gmail account you want to import from.
2. Click the gear icon in the upper right corner of the page and select Settings.
3. Go to the accounts and import section.
4. Then click on Add a mail account.
5. After that a popup will generated asking for the email address of the account from which you would like to fetch mail.
6. Enter the mail address and Click Next Step.
7. Enter the mail -id, password, pop server name(mail.domain.tld) and tick the checkbox as per your requirement after that click add account button.
8. All is set, now you can fetch mail from your desired server to your gmail account.