Setup GreyList ACLs
The primary use of this feautre is to setup milter-greylist whitelist.
It also offers a handy blacklist feature.
Access-lists (ACL) are used to do that.
ACL enable the administrator to specify complex conditions on sender IP, sender DNS address, sender e-mail address, and recipient e-mail address.
If support for DNSRBL was built-in, it is even possible to use DNSRBL in ACL.
- Select your instance and click on "Filters (Anti-spam,Antivirus tab)".
- Click on the Milter-greylist icon.
The first screen display the service status dedicated to the selected instance.
You can stop/start the service and refresh the service status.
- Click on "Access Control list" icon.
- The section display a table with default rules has example.
- Click on "Add" button under the table in order to add a new ACL.
An ACL rule have 3 sections:
- The method: The rule can be whitelist rule, a blacklist and a greylist.
- The rule type: The rule type defines the entry of an header message to match the pattern.
The pattern setting depends of the rule type.
It should be :
This clause is used to specify a netblock of source IP addresses.
The syntax is an IP address followed by a slash and a CIDR netmask.
Here is an example:
If the netmask is ommitted, /32 is assumed for an IPv4 address and /128 is assumed for an IPv6 address.
You should at least whitelist localhost (127.0.0.1/8), and if you have some user clients connecting to the machine, you should whitelist the addresses they connect from if you don’t want them to get error messages when sending e-mail.
milter-greylist is able to query external sources of information through various URL
String or regular expression searched in message body.
Example of content filtering for fighting image SPAM src[:blank:]*=(3D)?[:blank:]*["`]?[:blank:]*cid:
String or regular expression searched in message headers
This clause selects source machines based on their DNS name, performing a suffix search
From or recipient:
caracter "*" is allowed.
You can set for example
*@yourdomain.com or *@youdomain* or user.*@domain.*
This is used to select a DNSRBL
DNS Reverse Black List can be used to toggle an ACL.
They must be defined and named before they can be used. Here is an example which uses a bigger greylisting delay for hosts caught in the SORBS dynamic pool DNRSBL (this will include DSL and cable customers pools, which are well known to be massively infected by spamwares)
link a defined group that store items to this rule