Yeah, I know it would be easier for players to just get their act together and not make inappropriate sendings
and I know it's kind of a a non-trivial scripting task, but:
My suggestion is to give Clerk PCs the ability to screen sendings made by players.
How it would work is like this:
[INDENT]A PC approaches a messenger to make a sending
Moments later all currently logged on PCs in the Government Faction, inside the city, receive the message and are asked to veto the message if it's inappropriate.
If it is inappropriate (or if they have an otherwise compelling IC reason to block the sending) they use a widget they carry with them to vote against it.
If no blocks are registered, the sending will go off a few minutes after it's paid for.
[/INDENT]In principle it's as simple as that. Adding checks and balances - or even just making it a functionality that DMs can use - seems like it should be pretty simple additional features.
In the absence of a better system altogether (like using actual messenger NPCs who go to areas of the module and make relevant announcements for a price) I think this represents a good stop-gap solution.
While the sending system is very important from an OOC standpoint for the sake of keeping the action of the server coherent, I think it feels more like an OOC convenience than an immersive storytelling device. In that case, any step taken that would sensibly make the system feel less like a game mechanic and more like what it is - a device controlled by the government of Sanctuary as a tool of power, authority, and privilege- would be an excellent move indeed.
Plus, I think it would provide the maligned and unfortunate Clerk PCs with a tangible responsibility and a tangible ability to effect policy within the city.
Something, I fear, they are sorely missing.
I think it would take quite a lot of scripting to do.
Political PCs are pretty well known for blocking anything they don't like for the smallest of reasons, you'd never see any interesting sendings ever being made.
I think it's a bad idea for encouraging conflict. The occasional sendings will get through that shouldn't but it's probably better than the alternative of nothing but the most neutral and inoffensive of sendings getting through.
Would be much easier just to give people better access to an unauthorized sending system :S