We've been blocked by them in the past, it usually lasts at most 2-3 days. This has lasted nearly a week.
Anyone have any luck getting through to someone to get delisted?
Before you ask we:
1. Use MX toolbox to check multiple times a day if we are on any public blacklists, and I have used other services, we are not.
2. Have reached out to Yahoo/Verizon postmaster, they refuse to offer anything other than their guidelines that we are following.
3. Swapped to different servers with different IP's, they must block entire ranges because they immediately block any new IP's we swap to.
4. Dug through all outgoing traffic, nothing is being sent without being authenticated and no one has pinged as being compromised.
Any advice would be appreciated.