main.cf

myhostname = mail.SERVERNAME.com
mydomain = SERVERNAME.com
inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain, mail.$mydomain, www.$mydomain, ftp.$mydomain
mynetworks_style = host

#Then add the following to the same file:
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination,reject_non_fqdn_recipient
smtpd_sasl_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
virtual_alias_domains = pippasmallshop.com
virtual_alias_maps = hash:/etc/postfix/virtual
reject_rbl_client = zen.spamhaus.org