Postfix RBL Override

Let's examine the postfix rbl override and the associated configurations in more detail. With the aid of Skynats' server management support services, you will receive a thorough explanation of the entire procedure.

What is RBL?

The RBL module allows for the comparison of various message components, including sender IP addresses, URLs, emails, received header chains, SMTP data (such as the HELO domain), and more, to a variety of Runtime Black Lists (RBL), which are frequently provided by specialized DNS zones.

A set of RBL rules for well-known sources that are usually free for non-profit use are included in Rspamd (including fair usage policies). After discussing RBL, let's examine the postfix rbl override configuration.

RBL block overriding (whitelisting) in Postfix on Plesk

The following problem is likely to occur if we enable the proxy SMTP and use the Realtime Blacklist (RBL) on the Endian UTM Appliance to stop spam: Users occasionally complain that they can't access certain mailservers to receive emails. The majority of the time, this happens as a result of such mailservers being blacklisted after being used to send spam.

Postfix RBL Override Configurations

To configure the rbl override, follow the instructions below.

1. First, using any text editor, create the plain text files depicted in the following code:

/etc/postfix/rbl override.

2. Then add a comment line for adding the corresponding IPs, add one IP address to the whitelist per line, and then hit OK. The appearance will be similar to this: # Whitelisting the following - customer domain.com - 11/15/20131.2.3.4 OK.

3. From the /etc/postfix/ directory:postmap hash:rbl override, execute the following command:

4. Make the following modification to:

/etc/postfix/main.cf:smtpd_recipient_restrictions = permit_mynetworks, check_client_access pcre:/var/spool/postfix/plesk/no_relay.re, permit_sasl_authenticated, reject_unauth_destination Look like: smtpd_recipient_restrictions = permit_mynetworks, check_client_access hash:/etc/postfix/rbl_override, check_client_access pcre:/var/spool/postfix/plesk/no_relay.re, permit_sasl_authenticated, reject_unauth_destination

5. Restart postfix; typically "/etc/rc.d/init.d/postfix restart" on CentOS/RHEL/Scientific, or "postfix restart" on other distributions.