Whitelist specific domain from Spamhaus SBLCSS

[bond007]

Hello,

I’ve searched for ‘SBLCSS’ on the forum but wasn’t able to find how I can whitelist domains in my MiaB installation from this Spamhaus query. I have a customer that mentioned a specific domain was blocked multiple times.

In the logs it states the following:
Jul 17 00:00:00 mail postfix/smtpd[8940]: NOQUEUE: reject: RCPT from <host>[<ipv6>]: 554 5.7.1 Service unavailable; Client host [<ipv6>] blocked using zen.spamhaus.org; https://www.spamhaus.org/sbl/query/SBLCSS; from=<info@domain.tld> to=<mailbox@sample.tld> proto=ESMTP helo=<host>

How can I whitelist a specific domain? Thanks in advance!

[openletter]

It’s one of these two lines in /etc/postfix/main.cf:

smtpd_sender_restrictions=reject_non_fqdn_sender,reject_unknown_sender_domain,reject_authenticated_sender_login_mismatch,reject_rhsbl_sender dbl.spamhaus.org
smtpd_recipient_restrictions=permit_sasl_authenticated,permit_mynetworks,reject_rbl_client zen.spamhaus.org,reject_unlisted_recipient,check_policy_service inet:127.0.0.1:10023

I think it’s smtpd_recipient_restrictions, so you 'd have to figure out a way to bypass the check for an address or domain.

According to postconf(5), smtpd_relay_restrictions is processed before smtpd_recipient_restrictions, so if you follow my unsupported modification guide on blocklists:

How to create private blocklist

How to create private blocklist This will create a blocklist that will apply to sender from for all email received by the server: Create the rules list file: $ sudo nano /etc/postfix/sender_access Add to the file the desired action or actions: username@example.com DISCARD example.net DISCARD Note that the DISCARD option will recieve the mail to the server and silently delete it without delivering to any inboxes. This is generally preferable to the REJECT option which will send a messag…

But instead add to /etc/postfix/sender_access using OK action:

username@example.com	OK
example.net				OK

I think postfix will accept the message for delivery.

[bond007]

Thanks, I have performed those suggested changes. I hope it helps, I’ll let you know when I hear from them.