diff --git a/mailcow/src/mailcow-dockerized/data/Dockerfiles/netfilter/server.py b/mailcow/src/mailcow-dockerized/data/Dockerfiles/netfilter/server.py
index 08c8727..1adcf59 100644
--- a/mailcow/src/mailcow-dockerized/data/Dockerfiles/netfilter/server.py
+++ b/mailcow/src/mailcow-dockerized/data/Dockerfiles/netfilter/server.py
@@ -123,10 +123,8 @@
     time.sleep(10)
     with lock:
       filter4_table = iptc.Table(iptc.Table.FILTER)
-      filter6_table = iptc.Table6(iptc.Table6.FILTER)
       filter4_table.refresh()
-      filter6_table.refresh()
-      for f in [filter4_table, filter6_table]:
+      for f in [filter4_table]:
         forward_chain = iptc.Chain(f, 'FORWARD')
         input_chain = iptc.Chain(f, 'INPUT')
         for chain in [forward_chain, input_chain]:
@@ -198,14 +196,7 @@
         if rule not in chain.rules:
           chain.insert_rule(rule)
     else:
-      with lock:
-        chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), 'MAILCOW')
-        rule = iptc.Rule6()
-        rule.src = net
-        target = iptc.Target(rule, "REJECT")
-        rule.target = target
-        if rule not in chain.rules:
-          chain.insert_rule(rule)
+      pass
     r.hset('F2B_ACTIVE_BANS', '%s' % net, cur_time + BAN_TIME)
   else:
     logWarn('%d more attempts in the next %d seconds until %s is banned' % (MAX_ATTEMPTS - bans[net]['attempts'], RETRY_WINDOW, net))
@@ -227,14 +218,7 @@
       if rule in chain.rules:
         chain.delete_rule(rule)
   else:
-    with lock:
-      chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), 'MAILCOW')
-      rule = iptc.Rule6()
-      rule.src = net
-      target = iptc.Target(rule, "REJECT")
-      rule.target = target
-      if rule in chain.rules:
-        chain.delete_rule(rule)
+    pass
   r.hdel('F2B_ACTIVE_BANS', '%s' % net)
   r.hdel('F2B_QUEUE_UNBAN', '%s' % net)
   if net in bans:
@@ -258,20 +242,7 @@
         chain.delete_rule(rule)
         r.hdel('F2B_PERM_BANS', '%s' % net)
   else:
-    with lock:
-      chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), 'MAILCOW')
-      rule = iptc.Rule6()
-      rule.src = net
-      target = iptc.Target(rule, "REJECT")
-      rule.target = target
-      if rule not in chain.rules and not unban:
-        logCrit('Add host/network %s to blacklist' % net)
-        chain.insert_rule(rule)
-        r.hset('F2B_PERM_BANS', '%s' % net, int(round(time.time()))) 
-      elif rule in chain.rules and unban:
-        logCrit('Remove host/network %s from blacklist' % net)
-        chain.delete_rule(rule)
-        r.hdel('F2B_PERM_BANS', '%s' % net)
+    pass
 
 def quit(signum, frame):
   global quit_now
@@ -284,8 +255,7 @@
     unban(net)
   with lock:
     filter4_table = iptc.Table(iptc.Table.FILTER)
-    filter6_table = iptc.Table6(iptc.Table6.FILTER)
-    for filter_table in [filter4_table, filter6_table]:
+    for filter_table in [filter4_table]:
       filter_table.autocommit = False
       forward_chain = iptc.Chain(filter_table, "FORWARD")
       input_chain = iptc.Chain(filter_table, "INPUT")
@@ -368,41 +338,7 @@
           table.commit()
         table.autocommit = True
       except:
-        print('Error running SNAT4, retrying...') 
-
-def snat6(snat_target):
-  global lock
-  global quit_now
-
-  def get_snat6_rule():
-    rule = iptc.Rule6()
-    rule.src = os.getenv('IPV6_NETWORK', 'fd4d:6169:6c63:6f77::/64')
-    rule.dst = '!' + rule.src
-    target = rule.create_target("SNAT")
-    target.to_source = snat_target
-    return rule
-
-  while not quit_now:
-    time.sleep(10)
-    with lock:
-      try:
-        table = iptc.Table6('nat')
-        table.refresh()
-        chain = iptc.Chain(table, 'POSTROUTING')
-        table.autocommit = False
-        if get_snat6_rule() not in chain.rules:
-          logInfo('Added POSTROUTING rule for source network %s to SNAT target %s' % (get_snat6_rule().src, snat_target))
-          chain.insert_rule(get_snat6_rule())
-          table.commit()
-        else:
-          for position, item in enumerate(chain.rules):
-            if item == get_snat6_rule():
-              if position != 0:
-                chain.delete_rule(get_snat6_rule())
-          table.commit()
-        table.autocommit = True
-      except:
-        print('Error running SNAT6, retrying...') 
+        print('Error running SNAT4, retrying...')
 
 def autopurge():
   while not quit_now:
@@ -507,18 +443,6 @@
     rule.target = target
     if rule not in chain.rules:
       chain.insert_rule(rule)
-  # IPv6
-  if not iptc.Chain(iptc.Table6(iptc.Table6.FILTER), "MAILCOW") in iptc.Table6(iptc.Table6.FILTER).chains:
-    iptc.Table6(iptc.Table6.FILTER).create_chain("MAILCOW")
-  for c in ['FORWARD', 'INPUT']:
-    chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), c)
-    rule = iptc.Rule6()
-    rule.src = '::/0'
-    rule.dst = '::/0'
-    target = iptc.Target(rule, "MAILCOW")
-    rule.target = target
-    if rule not in chain.rules:
-      chain.insert_rule(rule)
 
 if __name__ == '__main__':
 
@@ -542,17 +466,6 @@
     except ValueError:
       print(os.getenv('SNAT_TO_SOURCE') + ' is not a valid IPv4 address')
 
-  if os.getenv('SNAT6_TO_SOURCE') and os.getenv('SNAT6_TO_SOURCE') != 'n':
-    try:
-      snat_ip = os.getenv('SNAT6_TO_SOURCE')
-      snat_ipo = ipaddress.ip_address(snat_ip)
-      if type(snat_ipo) is ipaddress.IPv6Address:
-        snat6_thread = Thread(target=snat6,args=(snat_ip,))
-        snat6_thread.daemon = True
-        snat6_thread.start()
-    except ValueError:
-      print(os.getenv('SNAT6_TO_SOURCE') + ' is not a valid IPv6 address')
-
   autopurge_thread = Thread(target=autopurge)
   autopurge_thread.daemon = True
   autopurge_thread.start()
diff --git a/mailcow/src/mailcow-dockerized/data/conf/postfix/main.cf b/mailcow/src/mailcow-dockerized/data/conf/postfix/main.cf
index a445b60..16dfd14 100644
--- a/mailcow/src/mailcow-dockerized/data/conf/postfix/main.cf
+++ b/mailcow/src/mailcow-dockerized/data/conf/postfix/main.cf
@@ -15,7 +15,7 @@
 alias_maps = hash:/etc/aliases
 alias_database = hash:/etc/aliases
 relayhost =
-mynetworks_style = subnet
+mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 172.22.1.0/24 [fe80::]/10 [fc00::]/7
 mailbox_size_limit = 0
 recipient_delimiter = +
 inet_interfaces = all