This is a feature that Outlook already has and corporate users expect. It's for making forwarding sensitive emails or any of their content require intent instead of being accidental.
If "accidental" is the true worry, display a confirmation/warning box before forwarding.
There are valid reasons to need to forward even e-mails marked confidential, including lawsuits, harassment cases, or even just asking your own lawyer before signing an agreement, among others.
Deciding when a piece of information should not have been forwarded is the job of the workplace or law, not the e-mail client.
> There are valid reasons to need to forward even e-mails marked confidential, including lawsuits, harassment cases, or even just asking your own lawyer before signing an agreement, among others.
Those are reasons for employees to forward an email, not the companies who Google is selling to.
> If "accidental" is the true worry, display a confirmation/warning box before forwarding.
Gmail supports other MUAs using IMAP and POP, so that doesn't work.
The fact that there are valid reasons to forward sensitive emails is why there is an escape hatch. It's only the accidental forwards and copies that this is meant to stop.
We can invent a new e-mail header X-Confidential: true, and clients will start to adopt the warning behavior over time. If Gmail supports it off the bat it will already cover a huge fraction of the market.
When designing APIs I find that bools are often a smell or a missed opportunity. What if, for example, there was an X-Intended-Audience?
That could be integrated with Active Directory, Groups, IAM etc within an organization to make the warning only pop up when a potential violation is occurring which helps avoid seeing the warning so often that it gets ignored (or accidentally send to the wrong confidential party as in medicine or law). It could also inform IT after the fact.
Or we can build a system that just works and doesn't rely on adoption by other clients. Yes if we had a header that everybody used and respected it would work. But that's a lot harder.
> Deciding when a piece of information should not have been forwarded is the job of the workplace or law, not the e-mail client.
You seem to misunderstand who controls the workplace. Within limits, the employer has significant control which increases or decreases based on jurisdiction.
Yes, these measures could limit an individual, but there are generally options like just asking the sender to forward a copy of an agreement/contract so that an outside counsel can review it. Denying review of a contract is a good way to get it invalidated.
I guess harassers could use this feature of the system to try to protect themselves, but it won't stop someone taking a photo from their phone. Realistically most organizations don't want to be complicit in that - even if they tend to default to silence - and HR only exists to protect the company.
The workplace can make that decision in advance and enforce it through Mobile Device Management. Which shows up as... the email client not letting you do the thing.
