saving outgoing mail

This is about:
How to save outgoing mail from your Machine(using postfix) to another Email address

In main.cf:
sender_bcc_maps = hash:/etc/postfix/copy-outboundMail

copy-outboundMail:
tmahesh@xyz.com backup@yzx.com

postmap copy-outboundMail (tell postfix system to hash this file)

postfix reload (I don't know if this is necessary)

/etc/init.d/postfix restart

there you go all mail you now send using smtp server as localhost will also go to backup@yzx.com