stephen@dcl-cs.UUCP (11/22/86)
I wonder how many of you have sent a mail message then wished you hadn't? I would like to see a facility for cancelling messages, similar to the way it is done by the usenet software: From: Stephen J. Muir <stephen@comp.lancs.ac.uk> To: Steve Kille <steve@cs.ucl.ac.uk> Subject: Re: an idea Control: cancel <861122065645.4523@dcl-csvax.comp.lancs.ac.uk> Please ignore the above message. If the target site had software to recognise the "Control" header, it could remove the original mail message from the user's mailbox (if it was still there), or from its mail queue if it had not been delivered, or from it's UUCP (or whatever) queue if it was being relayed, or whatever. Does anydody else like this idea? -- EMAIL: stephen@comp.lancs.ac.uk | Post: University of Lancaster, UUCP: ...!mcvax!ukc!dcl-cs!stephen | Department of Computing, Phone: +44 524 65201 Ext. 4120 | Bailrigg, Lancaster, UK. Project:Alvey ECLIPSE Distribution | LA1 4YR
paul@devon.UUCP (Paul Sutcliffe Jr.) (11/26/86)
In article <40@dcl-csvax.comp.lancs.ac.uk>, stephen@comp.lancs.ac.uk (Stephen J. Muir) writes: > I wonder how many of you have sent a mail message then wished you hadn't? I > would like to see a facility for cancelling messages, similar to the way it is > done by the usenet software: [ example deleted ] > If the target site had software to recognise the "Control" header, it could > remove the original mail message from the user's mailbox (if it was still > there), or from its mail queue if it had not been delivered, or from it's UUCP > (or whatever) queue if it was being relayed, or whatever. [ ... ] > Does anydody else like this idea? Depends. How soon after you have sent the mail will you decide that you don't want it sent after all. If the mail was sent to another account on your system, and that user was logged on, s/he may have read the message long before you issued the cancel command. Also, if your messsage was destined for a remote site, and your system talks to that site frequently (hourly polls), the same problem occurs. The cancel command may arrive too late to do any good. There are many variables playing here which would affect the usefulness of such a command, mostly time related. It is conceivable that your message passes through several backbone sites within the time span of an hour. Of course, your cancel command would travel as fast, but it would still be playing "catch up". Much depends upon how frequently the person receiving the message checks (and reads) his mail, too. Any other comments? -Paul -- Paul Sutcliffe, Jr. UUCP: {seismo,ihnp4,allegra,rutgers}!cbmvax!devon!paul Devon Computer Services COMPUSERVE: 76176,502 Allentown, Penna. +1 215 398 3776 "What this country needs is a good 5-cent *nickel*."
kre@munnari.oz (Robert Elz) (11/27/86)
In article <40@dcl-csvax.comp.lancs.ac.uk>, stephen@comp.lancs.ac.uk (Stephen J. Muir) writes: > I wonder how many of you have sent a mail message then wished you hadn't? I > would like to see a facility for cancelling messages, similar to the way it is > done by the usenet software: In article <119@devon.UUCP>, paul@devon.UUCP (Paul Sutcliffe Jr.) replies: > There are many variables playing here which would affect the usefulness > of such a command, mostly time related. The usefulness of such a command isn't what's really important, its its propriety. As readers of the Australian aus.mail newsgroup know, I very much like to make analogs between paper mail and e-mail whenever a question of how e-mail should behave arises. So, ask the same question about paper mail? Can you cancel paper mail after you have sent it? No. What's more, its (in most jurisdictions) illegal to try - mail once posted belongs to the recipient. It seems to me that the same is (should be) true of e-mail. Once a message is sent, its out of your control, and now its up to the recipient to decide what to do with it. Usenet is another matter altogether. Its outside world analog is a bulletin board. If you post something on a bulletin board, you're entirely free to go and take it down again. In a similar way you're free to cancel something that you post on usenet. The reasons why you might want to do this are similar too, if you are looking for some information, then receive it, it makes sense to remove your question to save others the expense of answering. The real solution is to think more before sending e-mail. Robert Elz {seismo,hplabs,ukc,mcvax}!munnari!kre
msb@dciem.UUCP (Mark Brader) (11/27/86)
> As readers of the Australian aus.mail newsgroup know, I very much > like to make analogs between paper mail and e-mail whenever a > question of how e-mail should behave arises. > > So, ask the same question about paper mail? Can you cancel paper > mail after you have sent it? You can if, as may be the case with office internal mail, it was you who delivered it and you did so by putting it in an open tray with the recipient's name on it. Now maybe you consider it improper to retrieve a memo delivered in this way, but I don't. I have used a mailer which kept track of read and unread mail, and allowed the sender to retract any unread mail. I think this is entirely reasonable, by the above analogy. (Many people on that system had their mailbox files readable to everybody, suggesting that the analogy was appropriate there.) HOWEVER, I would NOT advocate such a thing being put onto the UUCP net. Its communication links are much too insecure! The possibilities of messages being accidentally -- or maliciously -- canceled are just too unpleasant for mail cancellation to be a feasible idea. Mark Brader
bzs@bu-cs.BU.EDU (Barry Shein) (11/30/86)
I consider both reasons NOT to have such a feature compelling: 1. It is very unclear under what circumstances you can technically cancel mail. For example, we are an ARPANET node and a mail message sent is usually gone in seconds. 2. It is unclear whether this is an ethical practice, once you drop a letter in the mailbox you cannot retrieve it (legally.) I think it all falls under the heading of "don't make promises you can't keep" (a systems programming axiom I use often in such circumstances.) It is analagous to deleting a file, it is far better if the community learns that once a file is deleted it is most likely gone. If you want you can do with mail what some O/S's have done with files, mark them for sending and ask later if they really want it to be sent. I would find that annoying however (for letters, not files.) I think you are asking for huge troubles once you give your community any hint that a letter might be retracted, think about it. -Barry Shein, Boston University
gnu@hoptoad.uucp (John Gilmore) (12/02/86)
I worked with an email system (STSC's Mailbox) from 1972 through about
1980, which allows the canceling of messages. It was a useful feature.
I have occasionally used root privileges to cancel a message that I
have sent under Unix, before it got out (or got out to all recipients).
I find this a useful feature too, and wish it was easier and more general.
Mostly, the reason users of the Mailbox wanted to cancel a message is
because it contained an error of fact. E.g. announcing that a meeting
will occur at 1PM when it is actually at 2PM. Just getting the fixed
message is much cleaner than getting two conflicting messages.
Occasionally one's better sense takes hold after posting an ill-advised
message, and the fewer people who see it, the better. Both of these
reasons are used in the Usenet, which allows the canceling of articles.
I have not seen the ability to cancel a message abused by system
administrators, though I'm sure it has happened. When I left STSC in
1976, I sent a message to everyone in the company telling them why I
was leaving. The management requested that I cancel the message, but
when I disagreed, they did not attempt to override me and cancel it
themselves.
Note that the STSC Mailbox was not a single-system mail system. It started
that way, but was later enhanced to transfer messages transparently among
multiple machines. (No hostnames were used; everyone could be reached
on any machine, and their mail would migrate to their home machine,
except for special accounts like root, where the mail would sit on each
machine and not migrate.) If a message had been transferred to another
system, the cancel would also have to be transferred, and it would
not take effect immediately, of course. This is still better than
not being able to cancel at all.
Now for the Unix/Internet mail environment. Many things are different.
My best idea for cancellation in this environment is a convention in
the mail reading software which will cause it to suppress display of
a received message if a cancel message naming it is received. This
requires no changes to mail propagation software, and even has a useful
effect if the receiving site does not support cancellation, since the
recipient will get and read a little message that says "please cancel my
message XXXXX".
If such a scheme was considered reasonable, and was implemented, then
we could consider stopping cancelled messages while in transit (e.g. in
sendmail queues or uucp queues), or while stored in the user's mailbox
(e.g. delivery of a cancel message could remove a message from
/usr/spool/mail/$USER) rather than waiting for the user to call up a
mail reader which would do the job. But I think the main benefit of
cancellation (actually, STSC called it "withdrawl") is that *people*
will not see your message, rather than that *machines* will waste less
time moving it around.
--
John Gilmore {sun,ptsfa,lll-crg,ihnp4}!hoptoad!gnu jgilmore@lll-crg.arpa
"I can't think of a better way for the War Dept to spend money than to
subsidize the education of teenage system hackers by creating the Arpanet."atbowler@watmath.UUCP (Alan T. Bowler [SDG]) (12/02/86)
Assuming a reasonably secure mail implementation which keeps track of wheither a message has been read or not, there is no real reason why you can't cancel any message that has not yet been read. As Mark Brader observed the mail systems at Waterloo have allowed this for years. We have switched the implementation technique recently and will allow messages to remote machines be to be cancelled provided the cancel command reaches the recipient's mailbox before the the message has been read. (This ability of course stops when we read a gateway to a mail system that does not support a cancel). Some people seem to think that cancelling a message is immoral, but I really can't see that there is really any problem with it. It certainly is useful if a sender can retract an unread message whose content is no longer meaningful. I know I send enough messages like "comming for supper?" that have no read meaning if the person doesn't see them soon enough. Being able to retract them avoids bothering the person with unneeded mail.
brachman@ubc-cs.UUCP (Barry Brachman) (12/02/86)
In article <3700@watmath.UUCP> atbowler@watmath.UUCP (Alan T. Bowler [SDG]) writes: [...] >It certainly is useful if a sender can retract an unread message >whose content is no longer meaningful. I know I send enough messages >like "comming for supper?" that have no read meaning if the person >doesn't see them soon enough. Being able to retract them avoids >bothering the person with unneeded mail. X.400 allows you to specify an expiry date for a message. The expiry date indicates the date and time by which you consider the message to be "no longer valid and useful". The particular action that takes place upon expiry is unspecified by X.400, but the message could be deleted. A second cancellation mechanism involves deferred delivery. Specifying a deferred delivery time and date means that you don't want the message to be delivered before that time and date. After sending a message having a deferred delivery, you can issue a deferred delivery cancellation. The cancellation request may not succeed. In any case, you are informed about the results of the cancellation attempt for each recipient. In the event of failure to cancel delivery to a recipient the reason is given. ----- Barry Brachman Dept. of Computer Science Univ. of British Columbia Vancouver, B.C. V6T 1W5 .. {ihnp4!alberta, uw-beaver}!ubc-vision!ubc-cs!brachman brachman@cs.ubc.cdn brachman%ubc.csnet@csnet-relay.arpa brachman@ubc.csnet
roman@sigma.UUCP (Bill Roman) (12/03/86)
In article <3700@watmath.UUCP> atbowler@watmath.UUCP (Alan T. Bowler [SDG]) writes: > [...] I know I send enough messages >like "coming for supper?" that have no real meaning if the person >doesn't see them soon enough. Being able to retract them avoids >bothering the person with unneeded mail. Pardon my ignorance - can this be done with the "Expires:" line?
UH2@PSUVM.BITNET (12/03/86)
Email and P(aper)mail are not, and should not, be the same. The ability to at least try to cancel a message sendt by Email is one of its advantages, like not needing an envelope, and having multiple copies generated automatically. An advantage of Pmail is the security provided by the signature, and the ability to carry it around with you easily. Me? I like the idea of being able to try to cancel a message after it's been sent.
bill@sigma.UUCP (William Swan) (12/04/86)
In <948@sigma.UUCP> roman@sigma.UUCP (Bill Roman) writes: >In <3700@watmath.UUCP> atbowler (Alan T Bowler [SDG]): >>[...] I know I send enough messageslike "coming for supper?" that have >>no real meaning if the person doesn't see them soon enough. Being able >>to retract them avoids bothering the person with unneeded mail. >Pardon my ignorance - can this be done with the "Expires:" line? I don't think so. I don't think it's in the default mail header (I cannot recall ever seeing it except in news), and I don't know of any code that supports it. Would sure be a nice idea, though. -- chan 'eil Gaidhlig math againn /kha nel' gal'ig' mweh ag0n'/ (we do not speak good Gaelic)
paul@devon.UUCP (Paul Sutcliffe Jr.) (12/04/86)
In article <1337@munnari.oz>, kre@munnari.oz (Robert Elz) writes: > The real solution is to think more before sending e-mail. Just the point I was making in my previous posting on this subject, although I didn't come right out and say it. All I said was that I didn't think a cancel command would be very useful. -- Paul Sutcliffe, Jr. UUCP: {seismo,ihnp4,allegra,rutgers}!cbmvax!devon!paul Devon Computer Services COMPUSERVE: 76176,502 Allentown, Penna. Sarek: "Any message for your mother, Spock?" +1 215 398 3776 Spock: "Yes. Tell her 'I feel fine.'"
ken@rochester.ARPA (SKY) (12/05/86)
Moral issues aside, there are two stages at which a cancel request could arrive, when the message is still in the local queue, and when the message is already sent out. Sending out a cancel request in the latter case is fraught with security risks. Cancelling mail while it is not yet sent is analogous to retrieving it from your physical out box, *provided* you control the machine or the management allows you to do this. Analogy: your company allows you to retrieve mail before it goes out. This is a reasonable thing to want. But with the low latency of mail systems these days, this feature is probably of marginal value. So yes, think a little more before firing off in a hurry. As for saving other peoples time by cancelling mail which is no longer relevant, well they will take only a moment to decide if it is. Just about the same amount of time it takes you to compose a cancel request. Since other people will occasionally inconvenience you with no longer relevant mail too, I see that as a fair tradeoff. Ken
jimb@dopey.AMD.COM (Jim Budler) (12/13/86)
In article <8814UH2@PSUVM> UH2@PSUVM.BITNET writes: > >Email and P(aper)mail are not, and should not, be the same. The ability +--------------- I don't think this is, or should be true. If I send a proposal to people in my company, I want it to be considered. If they want to print it out to study, let them, but I'd prefer not to have to duplicate my effort by sending the letter by e-mail for speed, and by P-mail for legitimacy. To get this feeling of trust in e-mail the users have to feel that no-one is tinkering with the mail. +--------------- >to at least try to cancel a message sendt by Email is one of its >advantages, like not needing an envelope, and having multiple copies >generated automatically. > >An advantage of Pmail is the security provided by the signature, and >the ability to carry it around with you easily. > >Me? I like the idea of being able to try to cancel a message after >it's been sent. +--------------- Me? My mailbox file is mine (the disk space is the company's but the contents are mine), and I don't want anyone reading it but me. To remove a letter from it some one or some program must read it. I'll accept cancelling of the outbound mail queue, in the same sense that I accept that you can walk out to the mailbox in front of your house and remove a letter. Beyond that should remain forbidden. -- +==== Jim Budler ==== Advanced Micro Devices, Inc. ==== (408) 749-5806 ====+ | Compuserve: 72415,1200 | | E-mail: jimb@amdcad.AMD.COM | +======================== .signature = 4 lines ============================+