The Romans lasted two thousand years and it wasn't from not getting things right.
I think applying Occam's Razor here makes sense.
Is it more likely the smooth functioning of empire was made possible by:
A. Lousy mail service?
B. Fast and efficient mail service?
Of course the Romans were great, im not disputing that at all.Sure they were clever, sophisticated and much more. Whatever mail system they had would have been expensive and not affordable for average citizens. Every example you have given for a possible solution involves men at the top of the empire, governors, emperors and other men of enormous wealth.
Im not doubting there was an efficent communication system in the empire. However you have completely ignored the fact that the example i give was exclusively owned and run for the government. There is no mention of it being a public service that anybody could use.
The story of Paul is also completely the opposite of what would be required to run a large religioous organisation. At no stage does he acknowledge a wealthy benefactor. Surely given all his salutations he would have mentioned a thanks to warm the ego of the generous one who made it all possible.
Its not ever day somebody conquers the minds of half an empire on the scale of Pauls ministry. There are few individuals that belong to that club. Given the serious logistical problems isnt the simple answer, aka ORazor the entire thing is a fabrication. Letters are invented to give authority to points of view that the elites in the church wish to support. Mohammads Koran is similar. When he wants another wife, god gives him a vision.
Half the entire Pauline text are fakes. Every letter is warning the reader about other fake letters.
Can you tell me why its not simpler to believe that the extraordinary and rediculous claims are simply bullshite ?