...however openssh in base has it (of course), and the sendmail port has it as well. It looks fairly straightforward to import the patch from the sendmail port into base.
The current situation is surprising at least to the innocent user, in particular as /usr/share/examples/etc/blacklistd.conf references both smtp and submission but when importing that into /etc/blacklistd.conf it just doesn't work.
Kurt can you comment?
Greg Shapiro, who "owns" sendmail in base, refused to consider adding it.
So I added it to ports instead, so people could at least relatively painlessly benefit from it.
I've also submitted the patches to "upstream", but they are not interested in them either. (Open source sendmail doesn't seem to get much love and attention.)
(In reply to Kurt Lidl from comment #2)
Clear, understand. What a pain. I might consider patching my local source tree then...
It's no use to keep this PR open as base system sendmail for stable/11 won't have the feature.
This will not make it into 11.x (as no more releases will come) but we can revisit it for 13+