[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