I find it amazing that Zen, who are constantly voted ''Very bloody good'' by every ISP rating system in the country, don't have enough pull at Tiscali to just say ''look, jerks, we're Zen, get our mail server off your ridiculous blacklist''. It's a shame you can't threaten them somehow. Like, blocking all Tiscali IPs from your network and saying ...

I'm getting the exact same issue. Would it be possible for Zen to route Tiscali emails through another server, or better, talk to Tiscali and tell them to sort out their receiving mail servers? My experience tells me that non-Tiscali customers are going to have an impossible task trying to explain the issue to various levels of helpdesk support...