Network operators are increasingly playing dictator when it comes to email delivery. Since we operate several mail relay-related services (all authenticated, all secured), we are seeing mail providers do things that they really should not.
It might be adaptive rate limiting in a firewall, holding connections open / tarpitting, or just blocking mail but it’s getting annoying. Our request to mail providers and makers of this stuff: knock it off.
The Internet is blessed with a number of interoperable standards which allow for open communications. Larger operators are doing a cost analysis on why they have to buy more mail servers, which is admittedly spam. They look at the extra cost versus actually processing mail and the choice is pretty clear.
Our recent blockage with Comcast reminds us how fragile email is and how susceptible delivery is to intervention. Users on our service could not reach their Comcast address and Comcast simply refused to whitelist so we asked our users to contact Comcast. Hours later, they called us to work out the problem. In the meantime, mail was stuck in limbo.
As companies are responsible for a great amount of email and erect barriers, the Internet and the ability to communicate gets a lot less useful.