Synacor

Synacor is a cloud media provider that has a email filtering appliance with built in webmail access. They do provide a feedback loop for senders.

Other than the FBL, we don’t have much information about delivering to domains behind the Synacor appliance. Given they are partners with Cloudmark and Spamhaus it is likely they use at least some subset of their filtering technology.

Updated 3/13/2014