which e-mail manager is best to use with gmail,yahoo & hotmail................?

You can use Outlook or Outlook Express. At least hotmail, gmail and mybestmail can be managed from there, but not yahoo mail, only the paid version. I have a lot of servers and use them for different purposes, one for instance is reserved for messages from sites I suscribed to, so they will not fill the Spam folder of hotmail, for instance, wich disappears them too soon. Gmail is great but their label system can't really susbstitute the possibility of ordering by sender. So it's better seen from within Outlook. Since hotmail transformed to Windows Live Mail it is very good also.

I use all the email accounts

Thunderbird is my favorite, but it won't work with free Hotmail or Yahoo! accounts. You can get a free, third-party courier like YPOPs! to make it work with Yahoo!, but I'm not sure about Hotmail. Best to switch to POP providers, IMO.

I reccomend you to use thunderbird its great. I use this software client it supports almost all of them

windows default email client i mean outlook express is best......