HTML mail [was Re: FEL was Re: Hi]

Mon Aug 9 09:39:55 UTC 2010

On Mon, 2010-08-09 at 03:12 +0100, Marko Vojinovic wrote:
> So you are saying that I can write just a plain text message, label it
> as being html in the header, and the typical mail reader is going to
> pretend that any/all missing html tags are there, and then render and
> display the message as html? Well, I wasn't aware that mail readers
> got that sophisticated.

Nothing sophisticated about that, at all.  If you tell the client the
content is HTML, then the client tries to interpret it as being so.  Of
course, without there actually being any tags around the content, it'd
just treated as one great big blob of text, anyway.

The minimum presumed HTML tags of 
<html>
<head>
</head>
<body>
</body>
</html>

(the message goes between the body tags) don't provide any special
rendering.  Essentially, all they'd do is say "here be text."  If
they're not explictly put there by the authoring client, the rendering
client presumes that they're in the right place around the body content.
That's how HTML works.

It's not until you start using tags (around the content) which have
special purposes (paragraphs, line breaks, and all the other HTML
elements), that you're going to get any special rendering effects.

>  Can this behavior be turned off? I would guess yes, but... :-)

There are some clients that force the rendering of all content to be as
if it were plain text.  Sometimes this is necessary, because some twits
will send you HTML that's:

Black text on a black background, or other unreadable combinations.
Text that's 0.4 or 600 points in size (well, not literally those sizes,
but you should be able to get the gist of what I mean).  Hideous picture
backgrounds behind text, that make it impossible to read the text over
the top of it.  Images loaded off the WWW that show (via their web
access logs) when you've read their mail.  JavaScripting that exploits
weaknesses in your client, or is just so damn broken that it causes an
error without trying to be malicious.  And the list goes on...

Personally I find most HTML to be a waste of time, and a lot of it just
plain annoying (it renders as a complete mess, or just shoehorns lots of
crap onto a page).  But it does have some uses.  For instance, I used to
be regularly emailed the local cinema's schedule.  As a HTML table, it
was easy to read what was on when, and what day.  But as plain text, it
became an incoherent jumble, as line breaks and wraps occurred in bad
places.

-- 
[tim at localhost ~]$ uname -r
2.6.27.25-78.2.56.fc9.i686

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