$ sudo postconf|grep ^smtpd_.*_restrictions
smtpd_client_restrictions = permit_mynetworks, permit_sasl_authenticated,
smtpd_data_restrictions =
smtpd_end_of_data_restrictions =
smtpd_etrn_restrictions =
smtpd_helo_restrictions =
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated,
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, reject_unknown_client_hostname,

Nov 22 17:41:10 mazer postfix/smtpd[27976]: warning: hostname mta5.edonor.com does not resolve to address 206.188.11.53
Nov 22 17:41:10 mazer postfix/smtpd[27976]: connect from unknown[206.188.11.53]
Nov 22 17:41:11 mazer postfix/smtpd[27976]: NOQUEUE: reject: RCPT from unknown[206.188.11.53]: 450 4.7.1 Client host rejected: cannot find your hostname, [206.188.11.53]; from=<info@mbcherohub.club> to=<MYUSER@EMT-P.ORG> proto=ESMTP helo=<mta5.edonor.com>
Nov 22 17:41:11 mazer postfix/smtpd[27976]: disconnect from unknown[206.188.11.53]
Nov 22 17:41:22 mazer postfix/postscreen[27975]: CONNECT from [107.0.162.226]:26151 to [204.246.122.100]:25

alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
broken_sasl_auth_clients = yes
config_directory = /etc/postfix
home_mailbox = Maildir/
inet_interfaces = all
mailbox_command = /usr/lib/dovecot/deliver -c /etc/dovecot/dovecot.conf -m "${EXTENSION}"
mailbox_size_limit = 0
mailman_destination_recipient_limit = 1
message_size_limit = 102400000
mydestination = mazer.squad51.net, localhost, localhost.localdomain, localhost
myhostname = mazer.squad51.net
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
myorigin = /etc/mailname
owner_request_special = no
postscreen_dnsbl_action = drop
postscreen_dnsbl_sites = zen.spamhaus.org b.barracudacentral.org bl.spamcop.net
postscreen_dnsbl_threshold = 1
postscreen_greet_action = enforce
readme_directory = no
recipient_delimiter = +
relay_domains = lists.squad51.net
relayhost =
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtp_use_tls = yes
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
smtpd_client_restrictions = permit_mynetworks, permit_sasl_authenticated,
smtpd_helo_required = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated,
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, reject_unknown_client_hostname,
smtpd_sasl_auth_enable = yes
smtpd_sasl_authenticated_header = yes
smtpd_sasl_local_domain = $myhostname
smtpd_sasl_path = private/dovecot-auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_sender_restrictions =
smtpd_tls_auth_only = yes
smtpd_tls_cert_file = /etc/ssl/certs/mail.squad51.net.crt
smtpd_tls_key_file = /etc/ssl/private/mail.squad51.net.key
smtpd_tls_mandatory_ciphers = medium
smtpd_tls_mandatory_protocols = SSLv3, TLSv1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
tls_random_source = dev:/dev/urandom
transport_maps = hash:/etc/postfix/transports
virtual_alias_domains = emt-p.org
virtual_alias_maps = hash:/etc/postfix/virtual