Dovecot older version notice

Author: nico

README.md

@@ -519,6 +519,18 @@ EOF
 dovecot reload
 ```
 
+###### Older Dovecot version
+
+In case you're running a version of Dovecot older than 2.3.1, you will experience that the `auth_policy_check_before_auth` parameter does not exist.
+
+If this is the case, leave out these three parameters from the above configuration file:
+- `auth_policy_check_before_auth`
+- `auth_policy_check_after_auth`
+- `auth_policy_report_after_auth`
+
+The counting of blocked IPs will be doubled in your Control Center¹, but you'll still enjoy protection (¹ we're trying to find a workaround).
+
+
 ##### Postfix configuration
 
 To enable blocking of malicious IPs by Postfix (SMTP defence) do the following.
@@ -538,10 +550,23 @@ unix_listener /var/spool/postfix/private/auth {
 Then make Postfix use the Dovecot SASL server by adding the following to your Postfix config file (e.g. `/etc/postfix/main.cf`, or alternatively by using `postconf` CLI utility):
 
 ```
+smtpd_sasl_auth_enable=yes
 smtpd_sasl_path=/var/spool/postfix/private/auth
 smtpd_sasl_type=dovecot
 ```
 
+More documentation can be found on postfix' website:
+- [Configuring Dovecot SASL](http://www.postfix.org/SASL_README.html#server_dovecot)
+- [Enabling SASL in Postfix](http://www.postfix.org/SASL_README.html#server_sasl_enable)
+
+
+##### Blocklist use
+
+In order for Control Center to know that your Postfix/Dovecot are using the blocklist, please fill in their IP address on the Settings Page ("*Postfix public IP*").
+
+Currently the only supported setup for this is when Postfix and Dovecot are on the same IP address.
+
+
 ## Known issues
 
 ### High risk