said by squircle:In my archive of around 2 million spam messages, 77% (±2%) have originated from dynamic, ISP-assigned IP addresses (nothing close to "nothing practically").
Obviously this can vary from server to server for a number of reasons but this is what I was expecting.
said by squircle:Most customer-facing email servers I've run into accept mail on the submission port (587), including Google's and Microsoft's.
As any properly configured and administered mail server should be, it has only been a standard for over a decade.