HOWTO - Using the RBL

The MAPS (Mail Abuse Protection System) RBL (Realtime Blackhole List) is a means of identifying hosts that have been associated with the sending of spam mail. A full description of the service and the technology and ethics behind it can be found at http://maps.vix.com/rbl/ along with more general mail policy information at http://maps.vix.com/.

Exim can use the MAPS RBL and/or any other similarly defined service (ie you could make your own additional maps as well). To use exim for this you need to be running version 1.80 or later.

This documentation is for versions of exim before version 3.00, which are now considered obsolete. The current information can be found in the most recent version of this howto.

RBL Configuration Options

These are fully detailed in the Exim Specification Document. The specific section on RBL is here and the rbl directives are documented starting here

The 2 standard RBL configurations are:-

1. Use RBL to add a X-RBL-Warning: header which can be used by users for filtering

   rbl_domains = rbl.maps.vix.com
   no_rbl_reject_recipients
   rbl_warn_header
   

2. Use the RBL to reject mail from barred machines

   rbl_domains = rbl.maps.vix.com
   rbl_reject_recipients
   

In both cases machines can be explicitly removed from RBL control by adding their network addresses to the rbl_except_nets list.

The information to do more complicated manipulations can be found in the specification document and is outside the scope of this note.

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