Sendmail never stood the test of time and is pretty much abandoned now, replaced with Postfix. Guess in what language Postfix was written...
The idea is that language will not solve poorly designed software, but a developer that knows what he is doing like Wietse did with Postix. And Postfix stood the test of time pretty well, considering how complex it is.
Caveat: Saying “Just write it in rust” won’t change the fact that writing secure software is hard.
The only thing that will actually prevent security holes is attentive software engineers deliberately choosing to learn tools and practice habits to avoid security holes by design. The professional judgement of a lot of those engineers is leading them to choose to learn rust right now.
> Caveat: Saying “Just write it in rust” won’t change the fact that writing secure software is hard.
Absolutely. It's just that statistically the memory safety bugs have been the dominant percent of all the bugs, so rewriting core tools in a memory-safe language does make sense.