International Mailto URIs in IE7

mailto - limitations and paths forward

Dan's WebDAV 101 — Sat, 23 Aug 2008 03:23:59 GMT

The mailto tag used in html content is used to load the default mapi client (email client) on the user's

Avoiding an international mailto maelstrom

Sorting It All Out — Sun, 22 Jul 2007 03:37:12 GMT

The mail I got the other day from Wes Miller (yes, that Wes Miller!) forwarding someone else's question:

Avoiding an international mailto maelstrom

Noticias externas — Sun, 22 Jul 2007 03:21:24 GMT

The mail I got the other day from Wes Miller (yes, that Wes Miller!) forwarding someone else's question

re: International Mailto URIs in IE7

tihomir — Fri, 16 Feb 2007 18:54:43 GMT

In legacy mode if a character in the mailto URI has no representation in the destination codepage it will be represented with a question mark.

http://vistahelp.blogspot.com

re: International Mailto URIs in IE7

Dave Risney [MSFT] — Tue, 13 Feb 2007 23:51:06 GMT

@Richard Ishida

(2) Just to be clear, what you wrote is true for legacy mode only. In non-legacy mode IE7 a mailto URI may contain characters that are not directly representable in the encoding of the document containing the mailto URI and these characters will make it to the mail client.

Thanks again for your comments.

re: International Mailto URIs in IE7

Richard Ishida — Tue, 13 Feb 2007 23:33:50 GMT

Thanks for the clarifications.

Re (2), the danger being that some data is lost, ie. the euro sign becomes a question mark. I find that people aren't often clear about that. They may think that somehow the escape means that the character will somehow magically appear in the mail client, regardless of the encoding of their document. (One way to avoid this issue, of course, is to use UTF-8 everywhere.)

re: International Mailto URIs in IE7

Dave Risney [MSFT] — Tue, 13 Feb 2007 22:51:45 GMT

@Richard Ishida

Thanks for your comments. Responses to your points:

(3) If a hostname is passed through to the mail client whether its punycode encoded or not, its up to the mail client to display and resolve the hostname in the manner that the mail client chooses.

(2) What exactly do you mean by 'dangerous' here? In legacy mode if a character in the mailto URI has no representation in the destination codepage it will be represented with a question mark.

(1) I used NCRs in my examples in order to avoid font issues, and so I could easily convey the meaning of the text without explaining the char. encoding of the HTML snippet and its byte representation. I didn't mean to suggest that people should necessarily use NCRs. They should only use NCRs if their document's encoding can't directly represent that character.

re: International Mailto URIs in IE7

Richard Ishida — Tue, 13 Feb 2007 21:22:07 GMT

Hello Dave, Thanks for this useful post. It's great to see that you've followed the IRI spec for this. I have a couple of points.

[1] I think the article seems to imply that you should use NCRs (eg. ㄓ) to represent non-ASCII characters, whereas i think it is best to use the characters themselves whenever possible. You say "For example, if you wanted to include the previous example mailto URI in an HTML document you should use HTML encoding to represent the non US-ASCII character as ‘#x3113’." I would argue that you should say instead "For example, if you wanted to include the previous example mailto URI in an HTML document you should use Chinese characters to represent the non US-ASCII character, as in "?subject=ㄓ" (you can also use the escape ‘&#x3113’ if you have to)."

(On the other hand, (a) a bopomofo character is a bit of an odd choice, since bopomofo is rarely seen in Chinese text (just in the IME or ruby), and (b) with that character there may be a font issue for readers. I think you might have more success with an example such as the earlier used registration mark or an accented Latin character. For example, subject=Olá - where Olá is Portuguese for 'hello'. Just a suggestion.)

[2] I think it would be worthwhile to mention that for legacy mode it is dangerous to insert characters in the mailto that are not available in the encoding of the page - even if the NCR approach allows you to do so (eg. if you have a euro character in the mailto URI, but the encoding of the page is ISO 8859-1). Actually, i'm also curious to know what IE does in that situation.

[3] If mailto:name@xn--lba.example.com is passed through to the mail client, is it expected that the mail client will resolve the punycode?

re: International Mailto URIs in IE7

Viktor Krammer — Tue, 13 Feb 2007 19:58:05 GMT

You can also use the Quero IDN plug-in for IE to make IDN mailto links compatible with older mail clients such as Outlook Express. Quero automatically converts IDN email addresses to their ASCII representation. To write an email to somebody with an IDN address enter "mailto:name@®.example.com" in the Quero address box.

http://www.quero.at/

re: International Mailto URIs in IE7

Will — Tue, 13 Feb 2007 05:29:56 GMT

The article above should be retitled "YouTube does not generate valid RSS, which IE7 rightly refuses to render."