Can't force clients to respect outbox, and if even if all clients did some users might not want to be forced by their client to publish (and reveal their IP address) to unknown relays and demand to be given a choice. Other thing is there are two types of missed replies, Type A is replies that the replying party does not want the poster to be aware of (think screenshots of X posts with chatter underneath). Type B is posts that the replying party assumes/hopes the poster is aware of but actually the poster isn't aware and never will be. On nostr many users want "Type A Native" (no screenshotting, referencing the actual live post), and that complicates things, since you need a way for users to opt for Type A Native which isn't misunderstood by the client to be Type B. 

 nostr:nprofile1qqs8qy3p9qnnhhq847d7wujl5hztcr7pg6rxhmpc63pkphztcmxp3wgpz9mhxue69uhkummnw3ezuamfdejj7qgmwaehxw309a6xsetxdaex2um59ehx7um5wgcjucm0d5hsz9nhwden5te0dehhxarjv4kxjar9wvhx7un89uqaujaz I guess the challenge is to allow/disallow outboxing, on an npub level. 

 I fail to see how outbox forces users to publish to unknown relays.  The whole point is that clients that want to see your notes go to the relays that you publish on, isn't it? 

 Oh, right. 😂 Confused it with AUTH. 

 I don't quite get the Type A/B scenario. 

 Hey, I think you have client outbox confused with relay AUTH.