The config file format is the least of your worries (unless you're running Sendmail, ofcourse). It's about havimg to know about DKIM/SPF/dns weirdness/ etc, and having to stay up to date; about blacklists and greylists and the social dynamics around it; about mailbox storage and backups and users complaining about quotas and attachment sizes and that sort of shenanigans; about how will I let my users set auto responders and filters etc (just send them a link to the sieve man page! Lol); about having to worry about being called over the holidays because every custom server has its own peculiarities. And his talk about 'it used to be hard but not any more!' - yeah sure, just like the dozens of times people said that over the last decades? There's a 'year of Linux on the desktop' analogy in here somewhere.
Can't tell if you're serious or not - but if you are, just looking at man sieve is enough to understand why no sane person would give an average end user access to that. I mean I used it for many years but I'm a nerd weirdo.
> just looking at man sieve is enough to understand why no sane person would give an average end user access to that
You don't have to force an average user to hand edit Sieve files. You can put the same kind of GUI or web interface on top of a Sieve file that current mail providers put on top of whatever hand-built custom non-standard filtering rules system they currently have. To the end user it would look the same.
But for an end user like me, who already has a huge number of filter rules expressed in Sieve and would like to be able to upload them to an email provider, not supporting the Internet standard format for filter rules is a showstopper. I don't want to have to re-input all my filter rules into an email provider's web interface one by one. I want them to be able to understand the rules I already have in the Internet standard format I already have them.
" You can put the same kind of GUI or web interface on top of a Sieve file"
From a quick google, there does seem to be a Roundcube plugin for managing Sieve filters, but man yet another dependency (or two, as it seems you need a separate daemon as well) in an already brittle (by the time you get to this point) stack...
Look, I understand where you're coming from, and I used Sieve for many years, but it's 2019 - something is not an 'Internet standard format' when the number of users actually using it can be expressed with 4 or 5 digits at best... This horse is not just dead, we're snorting its ground up bones by now. Nobody caters to power users any more. Back when power users made up a sizeable portion of the internet population, yes, but not in 2019...
> something is not an 'Internet standard format' when the number of users actually using it can be expressed with 4 or 5 digits at best
Well, there is no other standard format at all, so basically you're saying we might as well just give up trying to have an internet standard for email filtering. That doesn't seem like a good outcome to me.
Yeah, that's the folk wisdom on sendmail. But really, since version 8.0, writing your own .cf (or reading it) should have been regarded as bizarre as crafting your own object files with an hex editor. And sendmail has served me well, over the years; its scariest feature (sendmail.cf) is also a strength - as a Turing complete programmiong language, it allows you to tie your incoming/outgoing mail in square knots, if you feel so inclined, or to solve some unforeseen mail routing configuration/problem/whatever. Of course, if you find someone that has gone to the lenght to write a _LOCAL ruleset that does it - and alas that is a creaft I do not possess, and is dying out. When it does, I will probably make the postfix jump.
I cannot claim prescience, because I started ont the trade when sendmail was THE mail program (though ed was no longer THE text editor): but consider, had I listened to the sendmail bashing crowd a couple years later I would have gone qmail (!!!). For not having done that, I thank the almighty weekly.
