We've moved a couple of hundred sites to a new server. Both servers are on version 11.48.0. The old server has the zen.spamhaus.org RBL enabled, as does the new one. However, email users on sites moved to the new server are getting outbound email blocked with the message "JunkMail Rejected". When you follow the spamhaus link, it's because the originating IP address is at a provider like Comcast or Verizon, and they require outbound mail to go through their servers. Here's the text from the link: So it looks like a policy block, not a spam block. This only happens on the new server, not on the old one, so that tells me there is a setting somewhere to turn it off. Any ideas? I don't want to turn off spamhaus entirely, just the PBL.