mail:# cat /etc/postfix/main.cf
smtpd_banner = $myhostname ESMTP
biff = no
append_dot_mydomain = no
myhostname = xxx
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
#transport_maps = hash:/etc/postfix/transport
myorigin = /etc/mailname
mydestination = mail, mail.xxx.cz, localhost, localdomain, localhost.localdomain
relayhost =
mynetworks = 127.0.0.0/8, xxx.xxx.xxx.xxx
box_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
message_size_limit = 31457280
disable_vrfy_command = yes
smtpd_recipient_limit = 30

smtpd_helo_required          = yes

smtpd_helo_restrictions      = permit_mynetworks,
                               reject_invalid_helo_hostname

smtpd_sender_restrictions    = reject_non_fqdn_sender,
                               reject_unknown_sender_domain,
                               permit_mynetworks,

smtpd_recipient_restrictions = reject_non_fqdn_recipient,
                               reject_unknown_recipient_domain,
                               permit_mynetworks,
                               reject_unauth_destination,
                               reject_unlisted_recipient,
                               reject_rbl_client bl.spamcop.net,
                               permit

smtpd_data_restrictions      = reject_multi_recipient_bounce,
                               reject_unauth_pipelining