There's no "Resend" or "Redirect" option in Yahoo! Mail Plus as far as I can see. I really miss that, and have to copy and paste a lot to get the wanted result which is to simply send an e-mail again as it was without any changes other than maybe recipients. I could save a draft of all e-mail I send to have this option, but it would be much easier if Yahoo! Mail made it possible to resend and/or redirect e-mail.
And then there's getting separate signatures for different account, but I have requested that so many times that I won't do it again here. Whooops, guess I just did.. :)