~ Is there any specific reason why you want it to be zero-fee?
Not, really. just testing stuff and i am very curious to know why that particular tx is being rejected!
i also believe that when mempool is empty and mining a block gives miners nearly $61,000 (big percentage of which is pure profit) the transactions must be free.
The Bitcoin network, as originally implemented, specifically set aside part of the block for priority transactions with zero fees to be included. Although I don't claim to have any insight to Satoshi's reasoning for doing that I'd lean towards that he probably wanted zero fees transaction to be available.
as far as i know, the purpose of fees are the following:
1. compensate miners for the work they are doing in case the block reward was small enough that it couldn't cover the cost of mining
2. prevent spam attacks sustainability as we saw multiple times.
@buwaytress
i am still using Electrum, however i create the raw transaction myself and ask Electrum to just sign it. just a workaround to force Electrum to sign 0 fees without checking it and preventing the creation. i usually broadcast it there too, without any issues.
but that smaller one is still being rejected because of priority!