Yes! It's possible! :)
Gmail can be considered as the best site to send emails. It combines various features of chatting with it too. Yahoo, Hotmail, AOL are other mail sending sites.
Yahoo, gmail, and facebook
Yahoo is known where your friends send you emails and you send them emails back.
You can directly send mails from Google to Yahoo. The Gmail supports this feature of sending mails. It can send mails to Yahoo server as well.
You can send emails to anyone else with an email address ... google, yahoo or whatever
You cannot send messages to Gmail without an account. However you need not to get a Gmail account only. You can also send it from yahoo mail like services.
You need to mark the high priority emails in Yahoo. By accessing the priority inbox, you can then choose to send the emails.
If you send a mail using Gmail, it will only be seen in the Gmail sent box. You can see it on a mobile in Blackberry too. However you cannot see the sent in Yahoo and Hotmail as they are different.
Gmail allows sending mails to other servers other than theirs. The mails can be sent with attachment to others like Yahoo mail. Hotmail is also a service to which it can easily send.
With Yahoo! Mail, you can not only send plain text emails or messages containing attachments.
Yes, sending and receiving messages on Gmail is free.
Yes