I would check steps 10 and 11 from your link.
I have not done it on the tablet but the port and encryption setting are very important.
You also might try using pop.gmail.com that is what this says, and I use.
And did you turn on the pop setting inside your Gmail web interface?

Unless Yahoo supports POP or IMAP you can not get your email outside of the webpage. Only Yahoo plus ($$$) supports pop, Wikipedia believes some countries may have free pop but Wikipedia did not know which ones.