Remove "Untrust RFC1918"

docs/firststeps-trust_networks.md

@@ -0,0 +1,11 @@
+Per default mailcow considers all networks as untrusted, except for its own IPV4_NETWORK and IPV6_NETWORK scope. Though it is reasonable in most cases, you may want to loosen this restriction under certain circumstances to allow connections from other networks.
+
+To change this behaviour override the default value of `mynetworks` parameter through the `data/conf/postfix/extra.cf` configuration file.
+
+**Important**: Do **not** remove the networks listed as `IPV4_NETWORK` and `IPV6_NETWORK` in your mailcow.conf. You should also keep local addresses. To add `1.2.3.4/32` it may look like the configuration below:
+
+```
+mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 [fe80::]/10 172.22.1.0/24 [fd4d:6169:6c63:6f77::]/64 1.2.3.4/32
+```
+
+Per default we use "mynetworks_style = subnet" to only include local networks we are part of.

mkdocs.yml

@@ -39,7 +39,7 @@ nav:
   - 'Rspamd UI': 'firststeps-rspamd_ui.md'
   - 'SNAT': 'firststeps-snat.md'
   - 'Sync job migration': 'firststeps-sync_jobs_migration.md'
-  - 'Untrust RFC 1918': 'firststeps-rfc-1918.md'
+  - 'Add trsteded networks': 'firststeps-trust_networks.md'
 - 'Models':
   - 'ACL': 'model-acl.md'
   - 'Password hashing': 'model-passwd.md'