This documentation never happened. It appears that Autoconfig worked quite well. There is a feature where Autoconfig can return a custom config per email address, if that is wanted. If anything, the world moved to a place where domains have a unified configuration for the entire domain.
Bug 564102 Comment 14 Edit History
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This documentation never happened. It appears that Autoconfig worked quite well. There is a feature where Autoconfig can return a custom config per email address, if that is wanted. If anything, the world moved to a place where most domains have a unified configuration for the entire domain, and handle differences on the server side.