I think I'm just going to remove this check. The primary goal was to reduce support costs related to users not restarting daemons after changing mail config, but I think the net cost of users hitting it is larger than the net cost of users not restarting stuff was.

Did we try some form of "automatically restart/stop daemons when needed"?

Some discussion in T7053. Mostly, I think it's just a ton of work to fix a problem that I think frequently (almost always?) boils down to users being out of their depth with server administration tasks.

users being out of their depth with server administration tasks.

I agree, but we can't add a check for that.

D14452 and similar seem nearly certain to obsolete this.