View Full Version : E-mail: copying of subject line when replying

09-27-2003, 12:37 PM
I rely on e-mail programs to automatically copy the subject when you reply. For instance you're sent an e-mail with a subject of say "test" and when you reply the new subject becomes "Re: test". I've never run accross an e-mail program that doesn't do that, but I'm not for certain that is standard behavior and so I don't tell people I'm relying on it. However it seems like some people never complete the confirmation process I've built-in which relies heavily on their e-mail program doing this. So I'm wondering if there are any e-mail programs that don't do this and I should make mention of this requirement.

thanks, SJP

09-27-2003, 05:18 PM
I belive you are right that programs do use the "re" when replying to an e-mail. I am most familair with the diffrent versions of Outlook and that I know of this is default and there is no option to turn it off. That said a user could always manually change the subject line which is something I have done before when replying. I have recieved e-mails like yours that are for confirmation and as a rule they mention not changeing the subject line or to make sure the subject line has something specific in it. I think it would be a good idea to make mention of it since the your system relies on it.


09-27-2003, 07:32 PM

Wildjoker makes a good point that people do have the ability to manually change the subject when they reply to an email, and that may be what caused your problem. I've always found in programming that you should never trust user input. Have you considered including some kind of tracking number in the message? Or perhaps you could include the tracking number in a way that isn't easy to change or forget... maybe set the reply-to email address to "(tracking#)@yourdomain.com" and parse the incoming message appropriately.

You could also maintain more control by having the user click on a link in their email that brings them to a dymanic form where they can type their reply or make their confirmation?

Just a few thoughts.

09-28-2003, 01:50 AM
And note that foregin language emailers may not use the exact letters "Re:" for the reply line, Germans for instance will have "AW:" in front of the subject.

It also useful to add an extra header in the headers that contains the tracking number or whatever you need. This can be a "X-Track...." or something.

09-28-2003, 02:46 AM
I should have been more specific about what I'm doing. I'm appending a confirmation number onto the end of the subject and that is what I parse for. I don't care if the replied subject starts with RE:, AW:, or whatever. Thanks for all the input. Embedding a link the user clicked on seems to be the most prevalent method. For this reason I can't help, but wonder if there are disadvantages using a custom header field like maybe e-mail programs only include a subset of them when the message is replied (To:, From:, Subject:). Otherwise this would be a good alternative.


09-28-2003, 09:25 AM
Hmm . . . I don't know the best way to do this, but I'll tell you what the Debian Lists (http://lists.debian.org) do. They do exactly what you were doing at first. That is they create a unique number and put it in the subject.

It looks like this . . .

Subject: CONFIRM s09281012312034

Then in the body of the message they say . . .

The address has NOT yet been subscribed to the mailing list.
To subscribe you need to confirm the subscription
request by sending an email to the address:

debian-user-request [AT] lists.debian.org

with the Subject header saying:

CONFIRM s09281012312034

With a reasonably good email program, a reply to this
message should be sufficient.

Do NOT remove or edit the CONFIRM ... text within the Subject header.
If it is removed or changed, the confirmation will fail!

In other words they don't try to do any extra work. If the user screws it up they will not be subscribed. If you look at the statistics (http://lists.debian.org/stats/debian-user.png) you'll see that this has worked fine for thousands of users. Here are statistics (http://lists.debian.org/stats/) for other debian lists.