Configure postfix to forward all email for a domain to another destination. (#Ubuntu #Trusty)

$>vim /etc/postfix/
virtual_alias_domains =
virtual_alias_maps = static:<>
#virtual_alias_maps = hash:/etc/postfix/virtual
$>service postfix reload

Any email sent to *, * will be redirected to, assuming of course that you setup the MX record for / to be the postfix server.

One risk is that any spam will also get forwarded; this is normally ok, but gmail etc will lower the sending MTA / IP score such that future emails that are not spam will still be treated as spam.