Can you set up a different "From" address in free email accounts like gmail or hotmail?

The reason I am asking is I have a website with free email forwarding but no mail boxes, so all the emails will goto another email account that are sent to my domain, but how do I reply "from" the right address without paying?
Can you set up a different "From" address in free email accounts like gmail or hotmail?
in gmail, go to settings%26gt;accounts





here you can use the "send mail as" feature - add an account and when you reply from forwarded or downloaded mail, the reply will be sent as if it is from the forwarded account