Craig, Thank you for your exhaustive reply - the list of checks along with current workarounds to achieve them are very helpful. I now know that I need to learn even more.
> OpenSMTPd's filter interface is not yet usable (last update 12/2014): > http://www.poolp.org/posts/2014-12-12/the-state-of-filters/ Slide 73 of https://www.openbsd.org/papers/eurobsdcon2017-opensmtpd.pdf mentions smtpfd - smtp filtering daemon. The slides are informative in terms of the thinking behind filters that OpenSMTPD plans to introduce. Some of the changes proposed in that talk like the modified grammar are now in -current. I may be wrong here but the filter/smtpfd might have been held back for post-6.4 introduction. > I heavily modified greyscanner to do a lot of the DNS checks. I found > the script's current maintainer extremely reluctant to implement even > very small bug fixes & general improvements, so I didn't even bother > presenting the vast bulk of my mods. But I stopped using greyscanner > about 5 years ago after setting spamd to be extremely aggressive, and > deploying Postfix's new postscreen (written in C). :( Would it be possible for you, in case you still have the mods, to please try sharing the diffs with the upstream? In case there might have been a change of heart, some of us might benefit from the added checks. Once smtpfd lands in -current, it could be further re-purposed as a filter. > I've not even begun to use IPv6 at all, for anything. I'm IPv4 only. Understood. I incorrectly assumed that you had enabled IPv6, and hence my question. I apologize. > I hope to use OpenSMTPd on external mail servers some day. Once the new smtpfd lands in -current, may be you could re-evaluate. > Cheers, > -- > Craig Skinner | http://linkd.in/yGqkv7 Regards, ab ---------|---------|---------|---------|---------|---------|---------|--
