F2B: update F2B after discussion in docker-mailserver#3256 (docker-mailserver#3288)

Author: georglauterbach

config-examples/fail2ban-jail.cf

@@ -8,7 +8,7 @@ bantime = 1w
 findtime = 1w
 
 # "maxretry" is the number of failures before a host get banned.
-maxretry = 2
+maxretry = 6
 
 # "ignoreip" can be a list of IP addresses, CIDR masks or DNS hosts. Fail2ban
 # will not ban a host which matches an address in this list. Several addresses
@@ -25,15 +25,12 @@ enabled = true
 
 [postfix]
 enabled = true
-# See https://github.com/fail2ban/fail2ban/blob/27294c4b9ee5d5568a1d5f83af744ea39d5a1acb/config/filter.d/postfix.conf#L58
-# `mode=aggressive` basically combines more filters to match more lines, and hence, apply rules
-# more aggressively. The same goes for the `postfix-sasl` jail.
-mode = aggressive
-
+# For a reference on why this mode was chose, see
+# https://github.com/docker-mailserver/docker-mailserver/issues/3256#issuecomment-1511188760
+mode = extra
 
 [postfix-sasl]
 enabled = true
-mode = aggressive
 
 # This jail is used for manual bans.
 # To ban an IP address use: setup.sh fail2ban ban <IP>

docs/content/config/security/fail2ban.md

@@ -29,7 +29,7 @@ hide:
 
 ### DMS Defaults
 
-DMS will automatically ban IP addresses of hosts that have generated 2 failed attempts over the course of the last week. The bans themselves last for one week.
+DMS will automatically ban IP addresses of hosts that have generated 6 failed attempts over the course of the last week. The bans themselves last for one week. The Postfix jail is configured to use `mode = extra` in DMS.
 
 ### Custom Files
 
@@ -39,10 +39,10 @@ This following configuration files inside the `docker-data/dms/config/` volume w
 
 1. `fail2ban-jail.cf` is copied to `/etc/fail2ban/jail.d/user-jail.local`
     - with this file, you can adjust the configuration of individual jails and their defaults
-    - the is an example provided [in our repository on GitHub][github-file-f2bjail]
+    - there is an example provided [in our repository on GitHub][github-file-f2bjail]
 2. `fail2ban-fail2ban.cf` is copied to `/etc/fail2ban/fail2ban.local`
     - with this file, you can adjust F2B behavior in general
-    - the is an example provided [in our repository on GitHub][github-file-f2bconfig]
+    - there is an example provided [in our repository on GitHub][github-file-f2bconfig]
 
 [docs-dms-config-volume]: ../../faq.md#what-about-the-docker-datadmsconfig-directory
 [github-file-f2bjail]: https://github.com/docker-mailserver/docker-mailserver/blob/master/config-examples/fail2ban-jail.cf

target/fail2ban/jail.local

@@ -8,7 +8,7 @@ bantime = 1w
 findtime = 1w
 
 # "maxretry" is the number of failures before a host get banned.
-maxretry = 2
+maxretry = 6
 
 # "ignoreip" can be a list of IP addresses, CIDR masks or DNS hosts. Fail2ban
 # will not ban a host which matches an address in this list. Several addresses
@@ -25,14 +25,12 @@ enabled = true
 
 [postfix]
 enabled = true
-# See https://github.com/fail2ban/fail2ban/blob/27294c4b9ee5d5568a1d5f83af744ea39d5a1acb/config/filter.d/postfix.conf#L58
-# `mode=aggressive` basically combines more filters to match more lines, and hence, apply rules
-# more aggressively. The same goes for the `postfix-sasl` jail.
-mode = aggressive
+# For a reference on why this mode was chose, see
+# https://github.com/docker-mailserver/docker-mailserver/issues/3256#issuecomment-1511188760
+mode = extra
 
 [postfix-sasl]
 enabled = true
-mode = aggressive
 
 # This jail is used for manual bans.
 # To ban an IP address use: setup.sh fail2ban ban <IP>