Well... in a way that is already doable.

Our centralized SFDB database is updated by SpamFilter reporting IPs that are added to the local "Cache IP blacklist". If an IP address is not added to the IP cache blacklist, it will never be reported to the SFDB database.

This said... please see the following in regards to the IP cache from our documentation:

Enable Cached IP Blocking - If an IP address sends more than a certain number of spam emails (3 by default) during a certain time interval (10 minutes by default), then it can be temporarily banned (blacklisted). All further connections from that IP address will be immediately rejected without allowing the sender to transmit any data. This should greatly reduce the load on the server. A banned IP address will be automatically removed from this temporary blacklist after a defined time interval (60 minutes by default). To prevent specific IPs to be added to this list, they can be added to DoNotAddIPToHoneypot SpamFilter.ini option.

That should thus do the trick!

Well.. that would be an unusual scenario. If an IP is present in the SFDB, it usually indicates that it is being used to send spam, and should thus be blacklisted.

If you're askign for that IP to be whitelisted from the SFDB, then you are, in a way, saying that you trust that IP not to send spam, and so it should not be added to the SFDB.

However, if you trust the IP not to send spam, that would mean that you should whitelist it entirely from all filters, as just like it's added to the SFDB, it could eventually appear in the RBL and SURBL servers, for example.

Big ISPs are abused by spammers, and they do sometimes send spam (until they identify the problem and eliminate it). Just like they appear in the SFDB filter, these ISPs will be listed in various RBL and SURBL servers as well. ...unless they have deals with them so that they are never listed with them. But in this case (blacklist servers admins whitelisting largre ISPs), it's like giving them a free pass for everything. If they are whitelisted, they can send a lot of spam that will go undetected. At that point, if they are trusted enough to be whitelisted by the blacklist providers, a SpamFilter admin may as well add them to a local whitelist...

We're open to discussion on this topic however, as usual, as we do value everyone's opinion. So I guess we'll see how this goes!