Lateral Thinking Puzzles. Let's do it again!

See above.

So the discovery has to do with how the message was delivered, not the specific content of the message?

See above.

The discovery went beyond both the content of the message and the way it was delivered. To be more precise (I think this is what you’re getting at), the discovery was not a new way of communicating messages.

Was the discovery made to deal with the reason the message was not delivered?

Was the recipient of the message the person who made the discovery?
Or was it the sender?
Someone else?
Was the discovery technological in nature?
Medical?

No to that one.

See above.

Was the sender trying to ask for financial assistance?

No to that one.

Was the sender the author of the message, or was the sender just passing along the message?

Was the reason it wasn’t sent as intended due to a shortage of some kind?

(BTW, you have the correct meaning of conveyance)

Was the sender trying to ask the recipient to provide something other than money?
Was the sender trying to report on something that would be of interest to the recipient?

Is the content of the message relevant at all? Or could this have happened in more or less the same way regardless of what the message was about?

Would it help to know more about the recipient?

Let me rephrase that. Was it a literary / artistic / musical work of any sort?

See above.

See above

See above.

Did it lead to the invention of some kind of device?
If so, was it a communication device? Telegraph? Telephone?

Did it lead to the invention of a form of transportation?

Edit: Was the message itself about an invention? And was the recipient a patent office?

Was the recipient in any way in a position of authority over the sender?
Was the sender in a position of authority over the recipient?
Would the message have been written in English?

The invention was not a device, much less a communication device. The message was not about an invention (neither this one nor another), and the recipient of the message was not a patent office.

See above.