[OT] need att.net postmaster contact

Hi, I have a mailing list host which runs into occasional issues with att.net/worlnet.att.net. Their abuse address has been responsive in lifting listings in their block list, but I've not been able to get anyone to respond about a more permanent solution, like setting up a feedback loop and whitelisting our netblocks. Can anyone contact me or direct me to a manager/director in the postmaster group (off-list, of course)? Thanks much, Omar Thameen