This is not a relevant analogy because it's not under dispute that Clinton used her email address for personal conversations, and there is nothing in the Reddit post or the Hill news story that indicates whether we're talking about personal or official business emails.
If your employer tried to force Gmail to turn over to them all your emails with your spouse and friends, no matter the subject or content, you and Google would fight it. And rightly so.
The House GOP members of the Benghazi committee are trying their hardest to get their hands on Clinton's personal emails, to dig for embarrassing messages to release. They already have her official business emails; they have had them for years. And they have openly admitted that the entire purpose of the committee is to undercut her presidential campaign.