Graphic description of IRISRBL Service #subtitle Protect your mail servers from spam and false positive
How DNSbl works
IRISRBL is a DNSBL, a Blocking List; it is a database that is consulted in real time by e-mail servers to obtain an opinion of the reputation of the origin of an e-mail. The role of IRISRBL is to advise and provide an opinion to RedIRIS institutions on the reputation of specific IPs with respect to incoming electronic mail.
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The policy of the receiver decides the action
Each institution and in general each domain that decides to implement antispam filters is defining a policy and actions for accepting incoming e-mail. The receiver unilaterally decides to use IRISBL as a blocking list and what it does with the incoming e-mail coming from an IP included in the IRISRBL list. IRISRBL only indicates if an IP is or is not included in the database.
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- The receiver takes the decision to accept, label or reject e-mail messages depending on, among other factors, whether the IP of the sender is included in IRISRBL.
- The receiver looks up IRISRBL asking, "Is the IP of the sender in RBL?". IRISRBL automatically responds in real time to the query about the sender of the e-mail.
- RedIRIS does not intervene in the decision adopted by the receiver about what to do with the incoming e-mail from an IP included in IRISRBL.
- Instead of rejecting a message coming from an IP included in IRISRBL, the message can be labelled, which is very helpful for future analyses of the contents (spamassassin etc.).
- RedIRIS recommends that Institutions using IRISRBL block/reject the connection of IPs included in IRISRBL, instead of accepting them and then ending up storing them in the wastebasket. Rejecting and blocking an e-mail in an SMTP transaction means that the content of the message does not enter your domain, thus reducing the use of resources. We maintain a classical rule for electronic mail: If an e-mail cannot be delivered the sender must ALWAYS be made aware of this, and receive information about the causes of non-delivery.