Mail.app: sending from an address w/o adding it

This may be a really tricky question about Mail.app.

Basically I love using GMail with IMAP protocol, it keeps all my mails synced across every device I have. I have setup my GMail to retrieve and send my Live mail, by adding my @live.com address in Email Address in desktop Mail.app under Account Settings, I can send mails using Live mail address w/o adding an actual Live mail account.

So my real question is, is there any way to do this in iPhone Mail.app just like that?

Thanks in advance.