[zimpenfish]

> Generally, all followers on a single server share the same sharedInbox.

You mean that all followers of Celebrity X on instance Y will have a sharedInbox because they're a follower of Celebrity X? Apologies, I've only lightly read the spec and haven't really seen anything like this in there.

[nightpool]

No, sorry, what I mean is that all users on mastodon.social have a unique private inbox and then a "sharedInbox" value of "https://mastodon.social/inbox". Almost all deliveries (with appropriate "to" and "cc" targeting values that the receiving server can appropriately deliver to, i.e. individual actors or the special "followers" group for an actors) can be sent to the sharedInbox in bulk, but for private groups and some other special cases you may want to use direct delivery.