First of all I would research and download an
e-mail client or your PC probably already has Outlook Express or Netscape e-mail already installed. Call your ISP and get all the settings then you can send that huge 4MB e-mail with no problems (depending on your ISP's e-mail size limit).
Otherwise consisder FTP, ICQ, AIM, MSN, Bearshare, Morpheus some other direct means to transfer the e-mail.