.forwardin the $HOME directory.
The content of .forward is the full address to which mail is to be forwarded. For example, if your account contains a .forward file with
claude.cantin@nrc.cathen all mail sent to your account will be forwarded to claude.cantin@nrc.ca.
If you want to keep a copy locally, and forward a second copy, simply add a second line in .forward to include your own login. For example, if your local login is cantin:
claude.cantin@nrc.ca
cantin