Does a new feature give Gmail users control over how emails are used? No. Not really, no (update 2018/05/06: and I found out is even worst than it seemed).

Gmail’s new design will include a ‘Confidential Mode', says The Verge, that, unless I’m really missing something basic, sounds almost useless, and partly misleading.

This “Confidential Mode”, says the article, “lets Gmail users stop recipients from forwarding certain emails, or restricts the ability to copy, download, or print them”. Oh, and also “or set an expiration date on sent emails”.

“Stop Recipients”? Allow me a few questions:

• to begin with, as the article itself says, “this won’t stop people from taking a screenshot or a photo of an email”. This alone makes the features pretty useless. The discussion could and should stop here. But unless, again, I’m missing something…
• if the description above is accurate, that “feature” will limit as intended only recipients who also are Gmail users. If SomeGuy@gmail.com sends an email to an OtherGuy@someotherserver.com, instead, that OtherGuy, using standard email software, will happily print, download and forward everything he wants. No matter how much “confidential mode” was used on the Gmail sending end. You can set all the expiration dates you want, but once an email is in my computer, archived with my software, it stays there as long as I want.
• it’s even worst. Think to all the people who, like me, do have a Gmail address, but set it up to automatically forward all incoming email to another, NON-GMAIL address. If Gmail forwards to non-Gmail addresses even messages set by their Gmail senders to “Confidential Mode”, it makes the whole useless even in Gmail. If Gmail does not forward the confidential email outside Gmail, it becomes useless for everybody who, like me, wants or must have a “primary inbox” connected to a non-Gmail address

The conclusion? This “Gmail Confidential Mode” reminds me of:

• the embarrassing SaveAsWWF “format” that, in order to save trees, should have stopped people to print files
• in the email realm, the dumbest thing ever conceived to block spammers, that is Challenge-Response filters

and unless it is something completely different from what it seems from the first reports about it, the “Gmail Confidential Mode” is never going to work 100% as intended.

Update added on 2018/04/28

An article I only discovered not at TechCrunch points out an interesting effect of “confidential mode” that I had overlooked, but is a bit more substantial than the other advantages of this new “feature”:

[when sending email in "confidential mode"]... You can't stop anybody from taking a picture of the screen of course, but what's maybe more important here is that if anybody ever hacked the recipient’s account, that email with your confidential information will be long gone.

Update added on 2018/05/06

“The features of confidential mode come with various positive attributes and a number of limitations, but for some users may also be something else — they may be ILLEGAL for them to actually use!… And it’s important to note that we’re not talking only about the Gmail users themselves.” Full story: “New Gmail Features That May Be ILLEGAL for You to Use!".

Another potential issue with confidential mode that could be a much broader risk to many more persons"is phishing, as explained here.