I still don't understand why, for projects and similar topics-based discussion, we don't use NNTP instead of Email. Email is good for addressing specific people only, and you're supposed to have been part of the conversation since the beginning so it does apply to personal correspondence but it scales horribly bad for groups of people: - there is no included history. You need to manually download hand-crafted archive…
> - mailing lists software exist but they are another hack. There is no standard for subscribing or unsubscribing
There is a standard for unsubscribing: https://tools.ietf.org/html/rfc8058
And for subscribing, you can often open a mailto: link.