If you want to send email from your friend`s email address then you can use following services. keep in mind that it`s not actually send email from your friend`s mail address ,but the person who receive email see your friend`s email address in sender
Above all emkei.cz is my favourite because it provide some advance option like email-header, reply to,cc etc.
You can also send from your cmd ,but for that purpose you need S.M.T.P server name of your I.S.P. so use above services only for fun .
Posted by Shubham ;)