How do i login and use 80 Yahoo or Gmail accounts ?

How do i login and use 80 Yahoo or Gmail accounts ?

I am interested in knowing how to login and check 80 Yahoo emails on a single ip or on multiple ip's i'm brainstorming the best method possible to execute my ideas.I need recommendations please.

Thanks

Well, if you have dynamic IP. You can just reset your router every time you want to do a new login.

Is it a tool or software more details please.Last time i checked yahoo doesn't logon over an ip,does it work well with yahoo mails?