There is absolutely nothing wrong with procmail, and yes, it is DONE.
If we start talking "abandonware" we have lost the plot, OSS is like an old book, we just need reference/copyright libraries so all copies dont get lost.
In the case of procmail its really useful so the pay-for-distros RedHat, SuSE, ... should man up and take responsibility for long term support, even if it only takes the form of a Free Beer for some older/retired developer to do the security patches.
Just when Linux is getting real traction in the embedded space we do not want to screw our server, super-computer or desktop users.
Abandoning useful code, gratuitous breakage and the un-necessary and capricous glibc 'romprement gratuite d'année' ie the memcpy debacle ...Yes SSE code can be used fore something.