On Thu, 2023-12-28 at 18:52 +0100, Kirill A. Korinsky wrote: > Greetings, > > This list seems as the right place to discuss about > http://imperialat.at/dev/filter-dnsbl
As the author, I agree. :-) > > 1. I'd like to report a small bug: OpenSMTPD injects header X-Spam: Yes when > filter decided that it is junk, and this filter injects yes (in the lower > case). Is it a bug? I'm not aware about any specific standard when it comes to this header. smtpd has `strcasecmp(line, "x-spam: yes")` in mail.maildir.c, so the capitalisation isn't important there. However, if you use smtpd with filter-dnsbl as a filter before forwarding it to another server which does check this header in a case-sensitive manner it would matter. So unless you can point to a piece of software which checks it in a specific capitalisation I don't see a direct reason to fix it. > > 2. Is it possible to add support of white list(s)? Let pass the message if it > contains on that list and optionally adds X-Spam-DNSWL: Listed at ... header. I've thought about adding whitelist support, but it's tough... The RFC is explicitly vague on how to interpret responses, so there's no way to determine how a response it to be interpreted without extensive configuration either by the admin, or in the binary. The latter would require in-depth knowledge of the different lists on my end and actively maintain those, which I don't see myself doing. Another reason why I don't see myself supporting whitelists is because I don't see their value. Mail is whitelist based in principle, so what blocking feature is it supposed to overwrite and how is filter-dnsbl supposed to do this? And that's not even starting on the prioritisation of which list takes precedence. Do you have a specific use-case for whitelisting and if so, how would you suggest to implement it in a generic way without making the filter needlessly complicated? In short: I'm not against whitelists per se, but without the specific use-case and a good plan of how to implement it without turning it into a coding/admin nightmare I don't see it happening. > > The nice example of white list is dnswl.mail.abusix.zone > > Thanks. > > > > -- > wbr, Kirill > martijn@
