Can't do that with email. Email doesn't have the necessary protocols to keep a file from being copied, scrub file systems, or maintain external links to trusted time keeping sources or control over the hardware to prevent screenshots or other methods to save the data as it's being displayed to the user.

There are some possible partial implementations like encrypting a file and only allowing decryption and display on a remote server. But then what's the point of making it an email in the first place? And if the method for viewing the data is something like a website, that doesn't prevent screenshots or other ways of storing the data.

The only way to truly have self-destructing content of any kind is to use a device that's fully controlled, a sever that makes sure the device is not compromised, and a neutral third party you trust to keep all recipients from tampering with the server and devices. Otherwise, if one of the users gets control of any component, they will be able to compromise the system. Unfortunately, there are no trustworthy companies who aren't under pressure to profit fr your data or from governments to allow access to your data. So there can never be a commercial product like that. And email doesn't have any of this as it's designed to be portable, not controllable.

The thing with any of the available methods is someone can save the content easily on their end, so it's only self-destructing in terms of the server it's stored on.

"Self-destructing" is like fetch: it isn't gonna happen. Stop trying to make self-destructing happen!

(No, seriously: the ability to enforce self-destruction of a message on a computer implies a pervasive Hellscape of DRM. You really don't actually want that.)

No. This isn't a thing. Don't try to make it a thing.

Once something leaves your computer you lose control of it. The recipient can do whatever they want with the message. If you don't trust the recipient not to be malicious then don't send them anything sensitive. You can't untell a secret.

The email protocols don't natively support this, so yeah your best option is to embed or link to a webpage that becomes inaccessible after a set amount of time.

you could encrypt the emails body with a gpg key that's going to expire soon.

You can't. You might want to, but email just doesn't work that way. Sorry.

• using a PrivateBin or PasteBin link.

IIRC that’s essentially what ProtonMail is doing. If you send an email to another provider and set an expiration date. An email along the lines of "this email is encrypted; open this link to view its content" shows up in the recipients inbox.

This would work just as well with any pastebin or other "self-destructing" link, like you said. But for me the whole idea of self-destructing information doesn’t make much sense. Others have already mentioned that there is no way to ensure that a copy wasn’t made at any point. A simple screenshot would, for example, defeat the whole point.

Also clicking on links in emails still gives me a strange feeling. Maybe it’s just me but I’ve received so many phishing attempts over the years that I don’t really trust any links in emails.

I don’t want to discourage anyone trying or implementing such a system. What I want to say is that adding a link to a known resource is probably your best option.

Wouldn't work with me, I read text emails.

I'll see myself out...