Mailto protocol with Outlook Express

Question

Ok, so this is not the ideal place for this question, but a long search on the net and in these forums and hours of working on the problem have not produced more than a hack result.
Yet I am sure that like me most java web programmers in the end have to face this problem.
The problem (and we've all heard this before) is that Microsoft's email client behaves unlike all the others, whereas in an ideal world it should be possible to programme for all of them at the same.
Here's the problem if you will bear with me.
I would like a clickable link to open the default mail client, insert the email address, a subject, and a body, where users can then play around with it and add what they want before sending the email.
You can do this in two ways.
1) with a <form action="mailto:[email protected]">
then a hidden or text input field for the subject and a textarea for the body, and a submit button.
This doesn't work very well because it always URLencodes all the subject and body text, which arrives completely unreadable in Outlook Express - perhaps there's a solution to this, but anyway I want everything completely hidden with only the link visible.
2) Here is the second solution, which works up to a point.
<a href="mailto:[email protected]?subject=<%= subject %>&body=<%= body %>>some link text</a>
Now for the hard part - I can't get Outlook Express to accept html in any way.  Oddly enough it seems to accept ONE <br> for example, but if there are more than one it encodes the < and the > and the <br> appears in its literal form in the email.
Ok, so if you want carriage returns in Outlook Express just include %0A" and hey presto you have carriage returns in the body of the email.
But lets say I now want to format text bold or similar, which can't be done without html. And anyway "%0A" doesn't work with other email clients, where I end up with a horrible flat mess without carriage returns.
Now if I send html to most other email clients, they lap it up. Ok, so if we knew the name of the default email client, we might be able to do a bit of programming logic to send "%0A" to one and <br> to the other, but as far as I know there isn't a way to find out the name of the default email client, unlike for browsers.
If I save the email in Outlook Express as an .eml file and take a look at it, it is sticking in its own html, as it always does, but ignoring mine.
So here is my question: Is there a way of forcing Outlook Express to accept my html? This would enable me to programme for nearly all email clients and I would also be able to use formatted text.

Answer 1

I think to be honest that the answer is that Microsoft has (for once) stuck to the specification,Yes,.... a very strange thing for MS to have done. Normally, they would've added all kinds of special things.
Generally, I'd expect that the body value would be URL decoded first and then it would treat is as HTML (since plain text is no different then HTML, it just has no tags). However, that mailto protocol is fairly old and not so commonly used outside of defining the To address, so it wouldn't surprise me to hear that these things were implemented years ago and not touched since.