Hello Urs,
My take on your problem is the following: - SPF is bad and breaks mail delivery, don't use it. But, if someone defines SPF records, and they thus declare they want to shoot themselves into their feet, by all means, I encourage to block mails failing SPF, because that's what domain owners who define SPF records ask for. - everyone can setup blocking lists defining the oddest criteria for when an entry gets added. Someone in charge of a mailserver can decide based on his criteria, and his alone, what mails he wants to receive and what mail to reject. He can use whatever resources he wants, including bogus lists such as uceprotect. But, it would be prudent to inform yourself about what exactly you enable before you do so... - now, if someone deploys antispam gateways such as those from Sophos, and decides to just click "enable all block lists" or however that menu looks like, and with this enables lists such as uceprotect, then that person just cut their company off from a lot of valid mail. If he wanted to do that, it's his decision, but usually it helps to teach those admins about the errors of their ways, instead of blaming the list provider. - I personally consider uceprotect to be a rogue list with utopian views on how mail service works. Their unlist policy could be considered extortion, but the really responsible party is whoever enables such a list on their servers.
just my personal views:)
Markus