ePrism User Guide - EdgeWave

RBL (Real-time Blackhole List)
RBL (Real-time Blackhole List)
RBLs contain the addresses of known sources of spam and are maintained by both commercial
and non-commercial organizations. The RBL mechanism is based on DNS. Every server that
attempts to connect to ePrism will be looked up on the specified RBL servers using DNS. If the
server is blacklisted, then a configurable action can be taken, such as rejecting the mail, or flagging
the message in its header or subject.
Note the following considerations when using RBL:
• If the RBL server is not available, the DNS request times out. This may affect performance and
requires monitoring for timed-out connections. Remove any servers which you do not use to
prevent time-outs.
• If a message that you want to receive is blocked by an RBL, add an item to the Pattern Based
Message Filtering list to "Trust" (to train for STA) or "Accept" (not train for STA) this
message.
• Choose your RBLs carefully. St. Bernard provides a default server, but we recommend you
review RBL providers (both commercial and free) as some servers are more reliable than
others, while some may not exist after a certain period of time. It is recommended for stability
and accuracy that a commercial RBL service be used.
Caution: The default RBL server in ePrism (rbl-plus.mail-abuse.org) is a commercial
RBL provider. To work properly, you must purchase a subscription to this service.
Configuring RBLs
Select Mail Delivery -> Anti-Spam from the menu. Click Realtime Blackhole List (RBL) to
configure RBLs.
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