Gmail Cannot Retrieve Hotmail via POP3

If you cannot retrieve Your Hotmail Account in Your Gmail Account via POP3, and got the following information in gmail

「Authentication failure: unknown user name or bad password. [Error="ProxyNotA...」

that is because All Hotmail accounts are being moved to Office 365 Servers, and that turns off the POP3 service, to reenable it, do the following in Hotmail:

Settings -> Options -> POP and IMAP -> Yes -> SAVE

Viola! You are able to access your Hotmail in Gmail again. 

Btw, Hotmail now allows forwarding email to Gmail too, you can try it in Settings -> Options -> Forwarding. I try it, it works, just that those email is marked by Gmail with "This message may not have been sent by:".