Starting with version 13.1 NoSpamProxy issues a warning if a used DNS server is blocked by a Spam URI realtime blocklist.
What is the significance of this?
This message informs you that the DNS server you are using and which you have configured in the Windows network settings or via the NoSpamProxy console under Configuration > Connected Systems > DNS Servers is blocked on the spam URI Realtime Blocklist. All DNS queries to the URIRBL are thus not answered and the spam protection is slightly weakened.
In most cases, the reason for this is that the free queries from the requesting DNS server are used up, since the lists only allow a certain number of free queries.
How can this be fixed?
The following options allow further requests beyond the free limit of spam URI realtime blocklists:
- To reduce requests, features like QNAME Minimization (RFC 7816) should be disabled for the NoSpamProxy Gateway role.
- Using your own DNS server, which only handles your requests (recommended)
- Change the DNS provider where the limit has not been used up (not recommended)
- Registration with the operator of the Spam URI Realtime Blocklist to send requests beyond the free limit (usually subject to a fee, DNS server independent)
Another DNS server can be set without much effort via the NoSpamProxy console under Configuration > Connected Systems > DNS Servers. After setting up a new DNS server, the service of the gateway role(s) must be restarted to clear the DNS cache.
We cannot make recommendations for DNS servers, because there are a large number of free providers in this area.
In addition, we would like to point out that this problem is not caused by NoSpamProxy and must be communicated with the corresponding operator of the DNS service.