No this is not the way to setup email groups. You need to use .forward file or using virtual tables. Do you wanna redirect/sed mail for local recipients (on same mail server) or remote mail server (user@dom.com, user@dom2.net) etc?

For local user open /etc/mail/aliases or /etc/aliases in wich aliases are specified in the format of <alias name>: <existing account>. The <existing account> should be substituted by one or more account names in form of a coma separated list.

For sales alias an e-mail sales@dom.net that should be delivered to all the users you, jerry, top etc:
save the changes and restart postfix MTA