Cfrgtkky

I just received mail from my server provider that my server is sending mails..i don't know about these mails and i never used smtp of that server before..can anyone guide me how this is possible?Thanks

Received: from `My IP`



    by smtp-1.moerdijk.net (8.15.2/8.15.2) with ESMTP id x0HB7vXV090789

    for ; Thu, 17 Jan 2019 12:08:03 +0100 (CET)

    (envelope-from jspark57@chollian.net)

    DMARC-Filter: OpenDMARC Filter v1.3.2 smtp-1.moerdijk.net x0HB7vXV090789

    Authentication-Results: smtp-1.moerdijk.net; dmarc=none (p=none dis=none) header.from=chollian.net

    Authentication-Results: smtp-1.moerdijk.net; spf=fail smtp.mailfrom=jspark57@chollian.net

    DKIM-Filter: OpenDKIM Filter v2.10.3 smtp-1.moerdijk.net x0HB7vXV090789

MAIN.cf

#soft_bounce = no



#

queue_directory = /var/spool/postfix



# The command_directory parameter specifies the location of all

# postXXX commands.

#

command_directory = /usr/sbin



#

daemon_directory = /usr/libexec/postfix





#

data_directory = /var/lib/postfix



# QUEUE AND PROCESS OWNERSHIP

#

#

mail_owner = postfix





#

#default_privs = nobody



# INTERNET HOST AND DOMAIN NAMES

#



#

#myhostname = host.domain.tld

#myhostname = virtual.domain.tld

#mydomain = domain.tld



# SENDING MAIL



#

#myorigin = $myhostname

#myorigin = $mydomain



# RECEIVING MAIL



#

#inet_interfaces = all

#inet_interfaces = $myhostname

#inet_interfaces = $myhostname, localhost

inet_interfaces = all



# Enable IPv4, and IPv6 if supported

inet_protocols = all



#proxy_interfaces =

#proxy_interfaces = 1.2.3.4



# See also below, section "REJECTING MAIL FOR UNKNOWN LOCAL USERS".

#

mydestination = $myhostname, localhost.$mydomain, localhost, example.com

#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain

#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain,

#       mail.$mydomain, www.$mydomain, ftp.$mydomain



# REJECTING MAIL FOR UNKNOWN LOCAL USER

#

# To turn off local recipient checking in the SMTP server, specify

# local_recipient_maps = (i.e. empty).

#

# The default setting assumes that you use the default Postfix local

# delivery agent for local delivery. You need to update the

# local_recipient_maps setting if:

#

# - You define $mydestination domain recipients in files other than

#   /etc/passwd, /etc/aliases, or the $virtual_alias_maps files.

#   For example, you define $mydestination domain recipients in

#   the $virtual_mailbox_maps files.

#

# - You redefine the local delivery agent in master.cf.

#

# - You redefine the "local_transport" setting in main.cf.

#

# - You use the "luser_relay", "mailbox_transport", or "fallback_transport"

#   feature of the Postfix local delivery agent (see local(8)).

#

# Details are described in the LOCAL_RECIPIENT_README file.

#

# The right-hand side of the lookup tables is conveniently ignored.

# In the left-hand side, specify a bare username, an @domain.tld

# wild-card, or specify a user@domain.tld address.

#

#local_recipient_maps = unix:passwd.byname $alias_maps

#local_recipient_maps = proxy:unix:passwd.byname $alias_maps

#local_recipient_maps =



# The unknown_local_recipient_reject_code specifies the SMTP server

# response code when a recipient domain matches $mydestination or

# ${proxy,inet}_interfaces, while $local_recipient_maps is non-empty

# and the recipient address or address local-part is not found.

#

# The default setting is 550 (reject mail) but it is safer to start

# with 450 (try again later) until you are certain that your

# local_recipient_maps settings are OK.

#

unknown_local_recipient_reject_code = 550



# TRUST AND RELAY CONTROL



# The mynetworks parameter specifies the list of "trusted" SMTP

# clients that have more privileges than "strangers".

#

# In particular, "trusted" SMTP clients are allowed to relay mail

# through Postfix.  See the smtpd_recipient_restrictions parameter

# in postconf(5).

#

# You can specify the list of "trusted" network addresses by hand

# or you can let Postfix do it for you (which is the default).

#

# By default (mynetworks_style = subnet), Postfix "trusts" SMTP

# clients in the same IP subnetworks as the local machine.

# On Linux, this does works correctly only with interfaces specified

# with the "ifconfig" command.

#

# Specify "mynetworks_style = class" when Postfix should "trust" SMTP

# clients in the same IP class A/B/C networks as the local machine.

# Don't do this with a dialup site - it would cause Postfix to "trust"

# your entire provider's network.  Instead, specify an explicit

# mynetworks list by hand, as described below.

#

# Specify "mynetworks_style = host" when Postfix should "trust"

# only the local machine.

#

#mynetworks_style = class

#mynetworks_style = subnet

#mynetworks_style = host



# Alternatively, you can specify the mynetworks list by hand, in

# which case Postfix ignores the mynetworks_style setting.

#

# Specify an explicit list of network/netmask patterns, where the

# mask specifies the number of bits in the network part of a host

# address.

#

# You can also specify the absolute pathname of a pattern file instead

# of listing the patterns here. Specify type:table for table-based lookups

# (the value on the table right-hand side is not used).

#

#mynetworks = 168.100.189.0/28, 127.0.0.0/8

#mynetworks = $config_directory/mynetworks

#mynetworks = hash:/etc/postfix/network_table



# The relay_domains parameter restricts what destinations this system will

# relay mail to.  See the smtpd_recipient_restrictions description in

# postconf(5) for detailed information.

#

# By default, Postfix relays mail

# - from "trusted" clients (IP address matches $mynetworks) to any destination,

# - from "untrusted" clients to destinations that match $relay_domains or

#   subdomains thereof, except addresses with sender-specified routing.

# The default relay_domains value is $mydestination.

#

# In addition to the above, the Postfix SMTP server by default accepts mail

# that Postfix is final destination for:

# - destinations that match $inet_interfaces or $proxy_interfaces,

# - destinations that match $mydestination

# - destinations that match $virtual_alias_domains,

# - destinations that match $virtual_mailbox_domains.

# These destinations do not need to be listed in $relay_domains.

#

# Specify a list of hosts or domains, /file/name patterns or type:name

# lookup tables, separated by commas and/or whitespace.  Continue

# long lines by starting the next line with whitespace. A file name

# is replaced by its contents; a type:name table is matched when a

# (parent) domain appears as lookup key.

#



#

#relay_domains = $mydestination



# INTERNET OR INTRANET



# The relayhost parameter specifies the default host to send mail to

# when no entry is matched in the optional transport(5) table. When

# no relayhost is given, mail is routed directly to the destination.

#

# On an intranet, specify the organizational domain name. If your

# internal DNS uses no MX records, specify the name of the intranet

# gateway host instead.

#

# In the case of SMTP, specify a domain, host, host:port, [host]:port,

# [address] or [address]:port; the form [host] turns off MX lookups.

#

# If you're connected via UUCP, see also the default_transport parameter.

#

#relayhost = $mydomain

#relayhost = [gateway.my.domain]

#relayhost = [mailserver.isp.tld]

#relayhost = uucphost

#relayhost = [an.ip.add.ress]



# REJECTING UNKNOWN RELAY USERS

#

# The right-hand side of the lookup tables is conveniently ignored.

# In the left-hand side, specify an @domain.tld wild-card, or specify

# a user@domain.tld address.

#

#relay_recipient_maps = hash:/etc/postfix/relay_recipients



# INPUT RATE CONTROL

#

# The in_flow_delay configuration parameter implements mail input

# flow control. This feature is turned on by default, although it

# still needs further development (it's disabled on SCO UNIX due

# to an SCO bug).

#

# A Postfix process will pause for $in_flow_delay seconds before

# accepting a new message, when the message arrival rate exceeds the

# message delivery rate. With the default 100 SMTP server process

# limit, this limits the mail inflow to 100 messages a second more

# than the number of messages delivered per second.

#

# Specify 0 to disable the feature. Valid delays are 0..10.

#

#in_flow_delay = 1s



# ADDRESS REWRITING

#

# The ADDRESS_REWRITING_README document gives information about

# address masquerading or other forms of address rewriting including

# username->Firstname.Lastname mapping.



# ADDRESS REDIRECTION (VIRTUAL DOMAIN)

#

# The VIRTUAL_README document gives information about the many forms

# of domain hosting that Postfix supports.



# "USER HAS MOVED" BOUNCE MESSAGES

#

# See the discussion in the ADDRESS_REWRITING_README document.



# TRANSPORT MAP

#

# See the discussion in the ADDRESS_REWRITING_README document.



# ALIAS DATABASE

#

# The alias_maps parameter specifies the list of alias databases used

# by the local delivery agent. The default list is system dependent.

#

# On systems with NIS, the default is to search the local alias

# database, then the NIS alias database. See aliases(5) for syntax

# details.

#

# If you change the alias database, run "postalias /etc/aliases" (or

# wherever your system stores the mail alias file), or simply run

# "newaliases" to build the necessary DBM or DB file.

#

# It will take a minute or so before changes become visible.  Use

# "postfix reload" to eliminate the delay.

#

#alias_maps = dbm:/etc/aliases

alias_maps = hash:/etc/aliases

#alias_maps = hash:/etc/aliases, nis:mail.aliases

#alias_maps = netinfo:/aliases



# The alias_database parameter specifies the alias database(s) that

# are built with "newaliases" or "sendmail -bi".  This is a separate

# configuration parameter, because alias_maps (see above) may specify

# tables that are not necessarily all under control by Postfix.

#

#alias_database = dbm:/etc/aliases

#alias_database = dbm:/etc/mail/aliases

alias_database = hash:/etc/aliases

#alias_database = hash:/etc/aliases, hash:/opt/majordomo/aliases



# ADDRESS EXTENSIONS (e.g., user+foo)

#

# The recipient_delimiter parameter specifies the separator between

# user names and address extensions (user+foo). See canonical(5),

# local(8), relocated(5) and virtual(5) for the effects this has on

# aliases, canonical, virtual, relocated and .forward file lookups.

# Basically, the software tries user+foo and .forward+foo before

# trying user and .forward.

#

#recipient_delimiter = +



# DELIVERY TO MAILBOX

#

# The home_mailbox parameter specifies the optional pathname of a

# mailbox file relative to a user's home directory. The default

# mailbox file is /var/spool/mail/user or /var/mail/user.  Specify

# "Maildir/" for qmail-style delivery (the / is required).

#

#home_mailbox = Mailbox

#home_mailbox = Maildir/



# The mail_spool_directory parameter specifies the directory where

# UNIX-style mailboxes are kept. The default setting depends on the

# system type.

#

#mail_spool_directory = /var/mail

#mail_spool_directory = /var/spool/mail



# The mailbox_command parameter specifies the optional external

# command to use instead of mailbox delivery. The command is run as

# the recipient with proper HOME, SHELL and LOGNAME environment settings.

# Exception:  delivery for root is done as $default_user.

#

# Other environment variables of interest: USER (recipient username),

# EXTENSION (address extension), DOMAIN (domain part of address),

# and LOCAL (the address localpart).

#

# Unlike other Postfix configuration parameters, the mailbox_command

# parameter is not subjected to $parameter substitutions. This is to

# make it easier to specify shell syntax (see example below).

#

# Avoid shell meta characters because they will force Postfix to run

# an expensive shell process. Procmail alone is expensive enough.

#

# IF YOU USE THIS TO DELIVER MAIL SYSTEM-WIDE, YOU MUST SET UP AN

# ALIAS THAT FORWARDS MAIL FOR ROOT TO A REAL USER.

#

#mailbox_command = /some/where/procmail

#mailbox_command = /some/where/procmail -a "$EXTENSION"



# The mailbox_transport specifies the optional transport in master.cf

# to use after processing aliases and .forward files. This parameter

# has precedence over the mailbox_command, fallback_transport and

# luser_relay parameters.

#





#

#mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp





#

# mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp

#

# The efficiency of LMTP delivery for cyrus-imapd can be enhanced via

# these settings.

#

# local_destination_recipient_limit = 300

# local_destination_concurrency_limit = 5

#

# 

#

# To use the old cyrus deliver program you have to set:

#mailbox_transport = cyrus



# The fallback_transport specifies the optional transport in master.cf

# to use for recipients that are not found in the UNIX passwd database.

# This parameter has precedence over the luser_relay parameter.

#

# Specify a string of the form transport:nexthop, where transport is

# the name of a mail delivery transport defined in master.cf.  The

# :nexthop part is optional. For more details see the sample transport

# configuration file.

#

# NOTE: if you use this feature for accounts not in the UNIX password

# file, then you must update the "local_recipient_maps" setting in

# the main.cf file, otherwise the SMTP server will reject mail for

# non-UNIX accounts with "User unknown in local recipient table".

#

#fallback_transport = lmtp:unix:/var/lib/imap/socket/lmtp

#fallback_transport =



# The luser_relay parameter specifies an optional destination address

# for unknown recipients.  By default, mail for unknown@$mydestination,

# unknown@[$inet_interfaces] or unknown@[$proxy_interfaces] is returned

# as undeliverable.

#

# The following expansions are done on luser_relay: $user (recipient

# username), $shell (recipient shell), $home (recipient home directory),

# $recipient (full recipient address), $extension (recipient address

# extension), $domain (recipient domain), $local (entire recipient

# localpart), $recipient_delimiter. Specify ${name?value} or

# ${name:value} to expand value only when $name does (does not) exist.

#

# luser_relay works only for the default Postfix local delivery agent.

#

# NOTE: if you use this feature for accounts not in the UNIX password

# file, then you must specify "local_recipient_maps =" (i.e. empty) in

# the main.cf file, otherwise the SMTP server will reject mail for

# non-UNIX accounts with "User unknown in local recipient table".

#

#luser_relay = $user@other.host

#luser_relay = $local@other.host

#luser_relay = admin+$local



# JUNK MAIL CONTROLS

#

# The controls listed here are only a very small subset. The file

# SMTPD_ACCESS_README provides an overview.



# The header_checks parameter specifies an optional table with patterns

# that each logical message header is matched against, including

# headers that span multiple physical lines.

#

# By default, these patterns also apply to MIME headers and to the

# headers of attached messages. With older Postfix versions, MIME and

# attached message headers were treated as body text.

#

# For details, see "man header_checks".

#

#header_checks = regexp:/etc/postfix/header_checks



# FAST ETRN SERVICE

#

# Postfix maintains per-destination logfiles with information about

# deferred mail, so that mail can be flushed quickly with the SMTP

# "ETRN domain.tld" command, or by executing "sendmail -qRdomain.tld".

# See the ETRN_README document for a detailed description.

#

# The fast_flush_domains parameter controls what destinations are

# eligible for this service. By default, they are all domains that

# this server is willing to relay mail to.

#

#fast_flush_domains = $relay_domains



# SHOW SOFTWARE VERSION OR NOT

#

# The smtpd_banner parameter specifies the text that follows the 220

# code in the SMTP server's greeting banner. Some people like to see

# the mail version advertised. By default, Postfix shows no version.

#

# You MUST specify $myhostname at the start of the text. That is an

# RFC requirement. Postfix itself does not care.

#

#smtpd_banner = $myhostname ESMTP $mail_name

#smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)



# PARALLEL DELIVERY TO THE SAME DESTINATION

#

# How many parallel deliveries to the same user or domain? With local

# delivery, it does not make sense to do massively parallel delivery

# to the same user, because mailbox updates must happen sequentially,

# and expensive pipelines in .forward files can cause disasters when

# too many are run at the same time. With SMTP deliveries, 10

# simultaneous connections to the same domain could be sufficient to

# raise eyebrows.

#

# Each message delivery transport has its XXX_destination_concurrency_limit

# parameter.  The default is $default_destination_concurrency_limit for

# most delivery transports. For the local delivery agent the default is 2.



#local_destination_concurrency_limit = 2

#default_destination_concurrency_limit = 20



# DEBUGGING CONTROL

#

# The debug_peer_level parameter specifies the increment in verbose

# logging level when an SMTP client or server host name or address

# matches a pattern in the debug_peer_list parameter.

#

debug_peer_level = 2



# The debug_peer_list parameter specifies an optional list of domain

# or network patterns, /file/name patterns or type:name tables. When

# an SMTP client or server host name or address matches a pattern,

# increase the verbose logging level by the amount specified in the

# debug_peer_level parameter.

#

#debug_peer_list = 127.0.0.1

#debug_peer_list = some.domain



# The debugger_command specifies the external command that is executed

# when a Postfix daemon program is run with the -D option.

#

# Use "command .. & sleep 5" so that the debugger can attach before

# the process marches on. If you use an X-based debugger, be sure to

# set up your XAUTHORITY environment variable before starting Postfix.

#

debugger_command =

         PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin

         ddd $daemon_directory/$process_name $process_id & sleep 5



# If you can't use X, use this to capture the call stack when a

# daemon crashes. The result is in a file in the configuration

# directory, and is named after the process name and the process ID.

#

# debugger_command =

#       PATH=/bin:/usr/bin:/usr/local/bin; export PATH; (echo cont;

#       echo where) | gdb $daemon_directory/$process_name $process_id 2>&1

#       >$config_directory/$process_name.$process_id.log & sleep 5

#

# Another possibility is to run gdb under a detached screen session.

# To attach to the screen sesssion, su root and run "screen -r

# <id_string>" where <id_string> uniquely matches one of the detached

# sessions (from "screen -list").

#

# debugger_command =

#       PATH=/bin:/usr/bin:/sbin:/usr/sbin; export PATH; screen

#       -dmS $process_name gdb $daemon_directory/$process_name

#       $process_id & sleep 1



# INSTALL-TIME CONFIGURATION INFORMATION

#

# The following parameters are used when installing a new Postfix version.

#

# sendmail_path: The full pathname of the Postfix sendmail command.

# This is the Sendmail-compatible mail posting interface.

#

sendmail_path = /usr/sbin/sendmail.postfix



# newaliases_path: The full pathname of the Postfix newaliases command.

# This is the Sendmail-compatible command to build alias databases.

#

newaliases_path = /usr/bin/newaliases.postfix



# mailq_path: The full pathname of the Postfix mailq command.  This

# is the Sendmail-compatible mail queue listing command.

#

mailq_path = /usr/bin/mailq.postfix



# setgid_group: The group for mail submission and queue management

# commands.  This must be a group name with a numerical group ID that

# is not shared with other accounts, not even with the Postfix account.

#

setgid_group = postdrop



# html_directory: The location of the Postfix HTML documentation.

#

html_directory = no



# manpage_directory: The location of the Postfix on-line manual pages.

#

manpage_directory = /usr/share/man



# sample_directory: The location of the Postfix sample configuration files.

# This parameter is obsolete as of Postfix 2.1.

#

sample_directory = /usr/share/doc/postfix-2.6.6/samples



# readme_directory: The location of the Postfix README files.

#

readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES

virtual_alias_maps = hash:/etc/postfix/virtual

sender_bcc_maps = hash:/etc/postfix/bcc

mailbox_command = /usr/bin/procmail-wrapper -o -a $DOMAIN -d $LOGNAME

home_mailbox = Maildir/

smtpd_sasl_auth_enable = yes

smtpd_sasl_security_options = noanonymous

broken_sasl_auth_clients = yes

smtpd_recipient_restrictions = permit_mynetworks permit_sasl_authenticated reject_unauth_destination

mailbox_size_limit = 0

allow_percent_hack = no

MASTER.Cf

# Postfix master process configuration file.  For details on the format

# of the file, see the master(5) manual page (command: "man 5 master").

#

# Do not forget to execute "postfix reload" after editing this file.

#

# ==========================================================================

# service type  private unpriv  chroot  wakeup  maxproc command + args

#               (yes)   (yes)   (yes)   (never) (100)

# ==========================================================================

smtp    inet    n       -       n       -       -       smtpd -o smtpd_sasl_auth_enable=yes

#submission inet n       -       n       -       -       smtpd

#  -o smtpd_tls_security_level=encrypt

#  -o smtpd_sasl_auth_enable=yes

#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject

#  -o milter_macro_daemon_name=ORIGINATING

#smtps     inet  n       -       n       -       -       smtpd

#  -o smtpd_tls_wrappermode=yes

#  -o smtpd_sasl_auth_enable=yes

#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject

#  -o milter_macro_daemon_name=ORIGINATING

#628      inet  n       -       n       -       -       qmqpd

pickup    fifo  n       -       n       60      1       pickup

cleanup   unix  n       -       n       -       0       cleanup

qmgr      fifo  n       -       n       300     1       qmgr

#qmgr     fifo  n       -       n       300     1       oqmgr

tlsmgr    unix  -       -       n       1000?   1       tlsmgr

rewrite   unix  -       -       n       -       -       trivial-rewrite

bounce    unix  -       -       n       -       0       bounce

defer     unix  -       -       n       -       0       bounce

trace     unix  -       -       n       -       0       bounce

verify    unix  -       -       n       -       1       verify

flush     unix  n       -       n       1000?   0       flush

proxymap  unix  -       -       n       -       -       proxymap

proxywrite unix -       -       n       -       1       proxymap

smtp      unix  -       -       n       -       -       smtp

# When relaying mail as backup MX, disable fallback_relay to avoid MX loops

relay     unix  -       -       n       -       -       smtp

        -o smtp_fallback_relay=

#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5

showq     unix  n       -       n       -       -       showq

error     unix  -       -       n       -       -       error

retry     unix  -       -       n       -       -       error

discard   unix  -       -       n       -       -       discard

local     unix  -       n       n       -       -       local

virtual   unix  -       n       n       -       -       virtual

lmtp      unix  -       -       n       -       -       lmtp

anvil     unix  -       -       n       -       1       anvil

scache    unix  -       -       n       -       1       scache

#

# ====================================================================

# Interfaces to non-Postfix software. Be sure to examine the manual

# pages of the non-Postfix software to find out what options it wants.

#

# Many of the following services use the Postfix pipe(8) delivery

# agent.  See the pipe(8) man page for information about ${recipient}

# and other message envelope options.

# ====================================================================

#

# maildrop. See the Postfix MAILDROP_README file for details.

# Also specify in main.cf: maildrop_destination_recipient_limit=1

#

#maildrop  unix  -       n       n       -       -       pipe

#  flags=DRhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient}

#

# ====================================================================

#

# The Cyrus deliver program has changed incompatibly, multiple times.

#

#old-cyrus unix  -       n       n       -       -       pipe

#  flags=R user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -m ${extension} ${user}

#

# ====================================================================

#

# Cyrus 2.1.5 (Amos Gouaux)

# Also specify in main.cf: cyrus_destination_recipient_limit=1

#

#cyrus     unix  -       n       n       -       -       pipe

#  user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -r ${sender} -m ${extension} ${user}

#

# ====================================================================

#

# See the Postfix UUCP_README file for configuration details.

#

#uucp      unix  -       n       n       -       -       pipe

#  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)

#

# ====================================================================

#

# Other external delivery methods.

#

#ifmail    unix  -       n       n       -       -       pipe

#  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)

#

#bsmtp     unix  -       n       n       -       -       pipe

#  flags=Fq. user=bsmtp argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient

#

#scalemail-backend unix -       n       n       -       2       pipe

#  flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store

#  ${nexthop} ${user} ${extension}

#

#mailman   unix  -       n       n       -       -       pipe

#  flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py

#  ${nexthop} ${user}

submission      inet    n       -       n       -       -       smtpd -o smtpd_sasl_auth_enable=yes

You have not configured any access restrictions for postfix, so it's effectively an open relay.

The very least you should do is to set either

mynetworks_style = host

or

mynetworks = 127.0.0.0/8, <your ip range you want to relay for>

and set

smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, defer_unauth_destination

This goes into main.cf. You may look at the examples provided and edit them.

Afterwards, use MX Toolbox to verify that you are no longer an open relay.