They replied back. They have *non standard* requirements for accepting inbound mail. In fact, the link the guy sent me is *dozens of pages long*. This is really really odd.....
Their "spam solution" is like curing a brain cancer patient by decapitating them to prevent spread to the rest of the body. Worse yet, they dont even tell the end users when mail is being blocked......
We are looking into it, but its ridiculous and we do not have this issue with any other ISP in the world. Apparently they don't like our whois record, but I'm not even 100% sure yet that this is the issue.
Some of these are "standard"... but many of them are not and unique to t-online........
https://postmaster.t-online.de/index.en.html
Their "spam solution" is like curing a brain cancer patient by decapitating them to prevent spread to the rest of the body. Worse yet, they dont even tell the end users when mail is being blocked......
We are looking into it, but its ridiculous and we do not have this issue with any other ISP in the world. Apparently they don't like our whois record, but I'm not even 100% sure yet that this is the issue.
Some of these are "standard"... but many of them are not and unique to t-online........
https://postmaster.t-online.de/index.en.html