/etc/postfix/main.cf

cat /etc/postfix/main.cf
# Some common configuration parameters
inet_protocols = ipv4
inet_interfaces = all
mynetworks_style = host

# IPv4 source for outbound mails
smtp_bind_address = xx.xx.xx.xx

# IPv6 source for outbound mails
#smtp_bind_address6 =

myhostname = admin.server.info
mydomain = admin.server.info.local
myorigin = $myhostname

smtpd_banner = $myhostname ESMTP i-MSCP 1.2.17 Managed

# Receiving messages parameters
mydestination = $myhostname, $mydomain
append_dot_mydomain = no
append_at_myorigin = yes
local_transport = local
transport_maps = hash:/etc/postfix/imscp/transport
relay_domains = hash:/etc/postfix/imscp/relay_domains
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases

# Delivering local messages parameters
mail_spool_directory = /var/mail

# Mailboxquota
# => 0 for unlimited
# => 104857600 for 100 MB
mailbox_size_limit = 0

# Message size limit
# => 0 for unlimited
# => 104857600 for 100 MB
message_size_limit = 0

biff = no
recipient_delimiter = +

local_destination_recipient_limit = 1
local_recipient_maps = unix:passwd.byname $alias_database

# i-MSCP Autoresponder parameters
imscp-arpl_destination_recipient_limit = 1

# Delivering virtual messages parameters
virtual_mailbox_base = /var/mail/virtual
virtual_mailbox_limit = 0

virtual_mailbox_domains = hash:/etc/postfix/imscp/domains
virtual_mailbox_maps = hash:/etc/postfix/imscp/mailboxes

virtual_alias_maps = hash:/etc/postfix/imscp/aliases

virtual_minimum_uid = 999
virtual_uid_maps = static:999
virtual_gid_maps = static:8

smtpd_helo_required = yes

smtpd_helo_restrictions = permit_mynetworks,
                          permit_sasl_authenticated,
                          reject_invalid_helo_hostname,
                          reject_non_fqdn_helo_hostname

smtpd_sender_restrictions = reject_non_fqdn_sender,
                            reject_unknown_sender_domain,
                            permit_mynetworks,
                            permit_sasl_authenticated

smtpd_relay_restrictions =

smtpd_recipient_restrictions =  reject_non_fqdn_recipient,
                                check_client_access hash:/etc/postfix/rbl_override,
                                reject_unknown_recipient_domain,
                                permit_mynetworks,
                                permit_sasl_authenticated,
                                reject_unauth_destination,
                                #reject_unlisted_recipient,
                                #reject_rbl_client,
                                #sbl.spamhaus.org,
                                #reject_rbl_client,
                                #cbl.abuseat.org,
                                #reject_rbl_client,
                                #dul.dnsbl.sorbs.net,
                                permit


smtpd_data_restrictions = reject_multi_recipient_bounce,
                          reject_unauth_pipelining

# Dovecot LDA parameters
virtual_transport = dovecot
dovecot_destination_concurrency_limit = 2
dovecot_destination_recipient_limit = 1

# Dovecot SASL parameters
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_authenticated_header = yes
broken_sasl_auth_clients = yes

# TLS parameters
smtpd_tls_security_level = may
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3
smtpd_tls_protocols = !SSLv2, !SSLv3
smtpd_tls_loglevel = 1
smtpd_tls_cert_file = /etc/imscp/imscp_services.pem
smtpd_tls_key_file = /etc/imscp/imscp_services.pem
smtpd_tls_auth_only = no
smtpd_tls_received_header = yes
smtp_tls_security_level = may
smtp_tls_mandatory_protocols = !SSLv2, !SSLv3
smtp_tls_protocols = !SSLv2, !SSLv3
smtp_tls_loglevel = 1
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt
non_smtpd_milters = unix:/clamav/clamav-milter.ctl
milter_connect_macros = j {daemon_name} v
smtpd_milters = unix:/clamav/clamav-milter.ctl
milter_default_action = accept

# Milyen esemenyrol kapjon a postmaster ertesitest
#  software : szoftverhiba miatt nem tudja a levelet tovabbitani
#  resource : eroforras problemek miatt nem tudja a levelet tovabbitani
#  protocol : protokolhiba, vagy nem futtathato parancs
#  policy   : policy megsertese miatt visszadobott levelek
#  delay    : keson tovabbitot level
#  bounce   : kezbesithetetlen level
notify_classes = resource, software, bounce