

Ask HN: Why doesn't email have a function so senders can pull back unread emails - andrewhillman

I remember back in the day, AOL MAIL had (they still might) a feature that let the sender pull back a delivered and unread email if the recipient was also on AOL mail.&#60;p&#62;Why has this feature not evolved into a core part of email across all mail providers (gmail, yahoo, live.com, aol.com etc.) today?
======
sveiss
Email delivery over SMTP works on a store-and-forward model: when you send an
email, it first goes to your outgoing mail server, which then connects to a
mail server at the destination domain and sends the message to it. The mail
server at the destination then has the responsibility of sending the mail on
to the receiving user (perhaps it gets routed through a spam filter, then to a
storage server to wait until the receiving user opens their mail client).

Because the source mail server forwards the message on, it loses control of it
-- the most it could do is send a "please delete this message I sent you and
forget I sent it" message to the mail server at the destination domain. The
destination mail server wouldn't be obliged to act on it -- it could have
forgotten where it forwarded the original mail on to, or it could instead
decide to send a 'Hey! Look what somebody doesn't what you to read!' message
in big flashing letters to the original recipient.

AOL and corporate mail systems can implement this because they control the
destination mail servers, as well as the sending mail server. On the wider
Internet, you'd need to replace SMTP with a protocol whereby the message is
stored near to the sender, rather than near the recipient, until the
destination user reads it. There are some good arguments in favor of a system
like this (it could make spammers bear more of the cost of sending their spam,
for instance), but uprooting a fundamental protocol and replacing it with
something else isn't an easy task to do on a network as big as the Internet.

~~~
csense
> uprooting a fundamental protocol and replacing it with something else isn't
> an easy task to do on a network as big as the Internet

It's a bit of work, but relatively straightforward if anyone really cares
about it enough to spend effort on it.

Add a new message to the SMTP protocol that says "I have mail for you, but
I'll only give you the headers right now. When the user opens it, you can call
me back and ask for the content." If the target server doesn't understand the
message, fall back to allowing the email to be recalled by implementing a
delay.

Publish an informal protocol spec before you publicly release any code; try to
get it accepted as an RFC.

Create an open-source reference implementation for the most popular open-
source email programs -- mail servers, mail clients, webmail platforms. Get it
accepted in the upstream of those projects.

As people start using it, they realize it's really good and start to demand it
of commercial implementations. As there's a published spec, the commercial
implementations end up being mostly compatible with each other and the open-
source work.

~~~
nanijoe
So what happens when I try to read the email and your server is offline? I'm
now stuck with the header that says "Important - Respond Immediately" without
any way of getting the content

------
tectonic
Gmail's ability to wait 30 seconds before actually sending the email so that
it can be canceled sort of provides what you want. I use it surprisingly often
when I realize I want to review or re-word something that I just sent.

~~~
1337biz
How do I exactly do that?(canceling an email within the first 30secs)

~~~
andrewhillman
You need to enable Gmail labs
[http://support.google.com/mail/bin/answer.py?hl=en&answe...](http://support.google.com/mail/bin/answer.py?hl=en&answer=29418)

------
cail
Technical issues aside, the way AOL implemented poses some issues from SPAM I
think.

With AOL I could check and if I can't unsend I know they opened the email. If
this worked across all email and I wanted to use email for nefarious purposes
I could use this to see, with great accuracy, exactly which email address that
I've sent to were active and opened the message. I can then target these
accounts more.

I feel like this could be a horrible idea.

------
bdunbar
Because there is now way I would let Some Guy reach into the mail store on my
server and fiddle around with the files there.

------
unimpressive
Explain how you implement this in a standard way across providers first.

------
rada
Off of top of my head: read email can be set back to "unread", email
notifications (you've received an email from X) running on multiple clients
such as it's open to interpretation whether email has been "delivered", client
rules (move email from sender X to folder X), etc.

------
Pitarou
GMail kinda has it. If you look in GMail Labs, you'll see the option to delay
sending an e-mail by 1 minute. That gives you 1 minute to change your mind. I
wish more mail clients had this feature.

------
Mankhool
I can do it on our internal corporate mail using Exchange.

------
wmf
It's extra work. Also, rules breed cheaters and then people whining about the
cheaters.

------
mattm
Because it's based on the snail mail system.

~~~
andyjdavis
This seems like it would be a big part of the reason why there is little
demand for this feature. There's no recall function with snail mail. We tend
to think of email as being like mail so take it as a given that it has the
same limitations.

