--- conf/master.cf.orig	2020-04-19 12:30:46.108385239 +0200
+++ conf/master.cf	2020-04-19 12:33:14.899620955 +0200
@@ -10,6 +10,11 @@
 #               (yes)   (yes)   (no)    (never) (100)
 # ==========================================================================
 smtp      inet  n       -       n       -       -       smtpd
+#amavis    unix  -       -       n       -       4       smtp
+#  -o smtp_data_done_timeout=1200
+#  -o smtp_send_xforward_command=yes
+#  -o disable_dns_lookups=yes
+#  -o max_use=20
 #smtp      inet  n       -       n       -       1       postscreen
 #smtpd     pass  -       -       n       -       -       smtpd
 #dnsblog   unix  -       -       n       -       0       dnsblog
@@ -17,6 +22,7 @@
 #submission inet n       -       n       -       -       smtpd
 #  -o syslog_name=postfix/submission
 #  -o smtpd_tls_security_level=encrypt
+#  -o content_filter=smtp:[127.0.0.1]:10024
 #  -o smtpd_sasl_auth_enable=yes
 #  -o smtpd_tls_auth_only=yes
 #  -o smtpd_reject_unlisted_recipient=no
@@ -65,6 +71,26 @@
 anvil     unix  -       -       n       -       1       anvil
 scache    unix  -       -       n       -       1       scache
 postlog   unix-dgram n  -       n       -       1       postlogd
+#localhost:10025 inet   n       -       n       -       -       smtpd
+#  -o content_filter=
+#  -o smtpd_delay_reject=no
+#  -o smtpd_client_restrictions=permit_mynetworks,reject
+#  -o smtpd_helo_restrictions=
+#  -o smtpd_sender_restrictions=
+#  -o smtpd_recipient_restrictions=permit_mynetworks,reject
+#  -o smtpd_data_restrictions=reject_unauth_pipelining
+#  -o smtpd_end_of_data_restrictions=
+#  -o smtpd_restriction_classes=
+#  -o mynetworks=127.0.0.0/8
+#  -o smtpd_error_sleep_time=0
+#  -o smtpd_soft_error_limit=1001
+#  -o smtpd_hard_error_limit=1000
+#  -o smtpd_client_connection_count_limit=0
+#  -o smtpd_client_connection_rate_limit=0
+#  -o receive_override_options=no_unknown_recipient_checks,no_header_body_checks,no_address_mappings
+#  -o local_header_rewrite_clients=
+#  -o local_recipient_maps=
+#  -o relay_recipient_maps=
 #
 # ====================================================================
 # Interfaces to non-Postfix software. Be sure to examine the manual
@@ -98,7 +124,7 @@
 # Also specify in main.cf: cyrus_destination_recipient_limit=1
 #
 #cyrus     unix  -       n       n       -       -       pipe
-#  flags=DRX user=cyrus argv=/cyrus/bin/deliver -e -r ${sender} -m ${extension} ${user}
+#  flags=DRX user=cyrus argv=/usr/lib/cyrus/bin/deliver -e -r ${sender} -m ${extension} ${user}
 #
 # ====================================================================
 #
@@ -131,3 +157,10 @@
 #mailman   unix  -       n       n       -       -       pipe
 #  flags=FRX user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
 #  ${nexthop} ${user}
+#
+#procmail  unix  -       n       n       -       -       pipe
+#  flags=R user=nobody argv=/usr/bin/procmail -t -m /etc/procmailrc ${sender} ${recipient}
+#
+#dovecot   unix  -       n       n       -       -       pipe
+#  flags=DRhu user=vmail:vmail argv=/usr/lib/dovecot/deliver -d ${recipient}
+#