Shallow Thoughts

Akkana's Musings on Open Source, Science, and Nature.

Wed, 05 Oct 2005

Blank Survey Messages

I love the messages I keep getting from having attended LinuxWorld a few months ago. They say:
Dear LinuxWorld Attendee:

That's it. That's all they say.

Well, unless you dig deeper. It turns out there's an html part, too, which actually does have content (asking me to participate in a survey). But I would never have seen that if I didn't know how to read the MIME structure of email messages.

You see, the message is sent as Content-Type: multipart/alternative, which means that there's a text part and an html part which are supposed to be equivalent. You can read either part and they should say the same thing. Lots of modern mailers, including Mozilla, mutt, pine, probably Opera, and even Apple Mail can now be configured to give preferences to the text part of messages (so you don't have to squint your way through messages written in yellow text on a pink background, or in tiny 6-point text that's too small for your eyes, and so that you can be assured of safety from web bugs and other snoopware which can be embedded in html mail). Any mailer so configured would show this message as blank, just as I'm seeing it in mutt.

It seems amazing that their web developers would go to the extra trouble of setting up MIME headers for multipart/alternative content, then not bother to put anything in the content. Why not just send as plain html if you don't want to create a text part?

I'd let them know they're sending blank messages, but tracking down a contact address seems like more trouble than it's worth. The mail purports to come from LinuxWorldConference&Expo@idg.com; the message references URLs from www.exhibitsurveys.com; the actual message (as seen in the headers) came from outboundmailexhibitsurvey.com. It's probably exhibitsurveys.com generating the bad email messages, but it's hard to say for sure.

Suggestion for web developers: if you write code to send out mass mailings, you might want to check the mail that's actually getting sent out. If your program generates more than one MIME attachment, it's a good idea to check all the attachments and make sure you're sending what you think you are. Look at the actual message structure, don't just glance at the message in the mail program you happen to use. The fact that a message displays in one mailer does not imply that it will display correctly for all users (especially for a survey aimed at Linux users, who use a wide variety of mailers on many platforms and are quite likely to set non-default options). If you don't know MIME, find someone who does to sanity-check your output ... or don't send multiple MIME attachments.

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[ 11:30 Oct 05, 2005    More tech | permalink to this entry ]