You can use Gmail as email client. Just like you do Outlook or other POP3 or IMAP clients out there. You just need to setup Gmail for POP3 and SMTP which is a lot easier than it seems in Google’s support articles. In this video, I briefly explained how to set it up so that you can use your Gmail account to send and receive emails for your other email accounts.
You just need to go to Gmail settings and “Accounts and Import” tab. And then configure the “Send mail as:” and “Check mail from other accounts:” sections as instructed.
Here is a short video on how to do it step by step: