starred/markdownlint

Fork 0

mirror of https://github.com/DavidAnson/markdownlint.git synced 2026-04-26 09:46:01 +03:00

[GH-ISSUE #1212] Umlauts like Ä, Ö, Ü in Mailadresses/URLs are not detected as normal letters #2488

New issue

Closed

opened 2026-03-07 20:08:14 +03:00 by kerem · 5 comments

kerem commented

2026-03-07 20:08:14 +03:00

Owner

Originally created by @leanderbuerkin on GitHub (May 14, 2024).
Original GitHub issue: https://github.com/DavidAnson/markdownlint/issues/1212

The Mailaddress

<küche@tf.de>

is automatically formatted to

<kü<che@tf.de>>
```.

Is that intended?

Originally created by @leanderbuerkin on GitHub (May 14, 2024). Original GitHub issue: https://github.com/DavidAnson/markdownlint/issues/1212 The Mailaddress ``` <küche@tf.de> ``` is automatically formatted to ``` <kü<che@tf.de>> ```. Is that intended?

kerem

2026-03-07 20:08:14 +03:00

closed this issue
added the
question
label

kerem commented

2026-03-07 20:08:15 +03:00

Author

Owner

@DavidAnson commented on GitHub (May 14, 2024):

MD034 reports: Bare URL used [Context: "che@tf.de"]

So it looks like the umlaut character is not allowed in an email address. That appears to be the case for the parser which limits that section to ASCII alphanumeric: https://github.com/micromark/micromark-extension-gfm-autolink-literal?tab=readme-ov-file#syntax

Rendering of the sample input via the parser markdownlint uses is the same as what happens on GitHub - the first two characters are not part of the link: https://dlaa.me/markdownlint/#%25m%3Ck%C3%BCche%40tf.de%3E%0A

So I think the current behavior is correct (and consistent with GitHub) based on how email addresses are defined and corresponding autolink behavior.

@DavidAnson commented on GitHub (May 14, 2024): MD034 reports: Bare URL used [Context: "che@tf.de"] So it looks like the umlaut character is not allowed in an email address. That appears to be the case for the parser which limits that section to ASCII alphanumeric: https://github.com/micromark/micromark-extension-gfm-autolink-literal?tab=readme-ov-file#syntax Rendering of the sample input via the parser markdownlint uses is the same as what happens on GitHub - the first two characters are not part of the link: https://dlaa.me/markdownlint/#%25m%3Ck%C3%BCche%40tf.de%3E%0A So I think the current behavior is correct (and consistent with GitHub) based on how email addresses are defined and corresponding autolink behavior.

kerem commented

2026-03-07 20:08:15 +03:00

Author

Owner

@leanderbuerkin commented on GitHub (May 15, 2024):

Alright, we could solve our problem from the other direction: kueche@tf.de is forwarded to the same e-mailaddress (or is the same address?).

@leanderbuerkin commented on GitHub (May 15, 2024): Alright, we could solve our problem from the other direction: <kueche@tf.de> is forwarded to the same e-mailaddress (or is the same address?).

kerem commented

2026-03-07 20:08:15 +03:00

Author

Owner

@DavidAnson commented on GitHub (May 15, 2024):

I doubt that would go to the same person. I think the recommendation is probably to "percent encode" the umlaut character. or maybe ask the person who owns that alias as this is probably something they have dealt with before.

https://en.m.wikipedia.org/wiki/Percent-encoding

@DavidAnson commented on GitHub (May 15, 2024): I doubt that would go to the same person. I think the recommendation is probably to "percent encode" the umlaut character. or maybe ask the person who owns that alias as this is probably something they have dealt with before. https://en.m.wikipedia.org/wiki/Percent-encoding

kerem commented

2026-03-07 20:08:16 +03:00

Author

Owner

@Qup42 commented on GitHub (May 16, 2024):

Thanks for the pointers. I found two workarounds that work, when markdown automatic links (<...>) are used.

<k%C3%BCche@tf.de> as suggested by you. Works as markdown automatic link but not as a GFM automatic link (meaning just k%C3%BCche@tf.de without <> does not work).
<mailto:küche@tf.de> works as well.

A quick note on standards: from a quick read I understand that basic SMTP does not allow non-ascii characters in addresses. SMTPUTF8 (RFC6531 through RFC6533) adds this but is only from around 2012 and thus quite new (atleast for an internet standard).

TL;DR: While this is annoying I expect that the workarounds are sufficient for us.

@Qup42 commented on GitHub (May 16, 2024): Thanks for the pointers. I found two workarounds that work, when markdown automatic links (`<...>`) are used. - `<k%C3%BCche@tf.de>` as suggested by you. Works as markdown automatic link but not as a GFM automatic link (meaning just `k%C3%BCche@tf.de` without `<>` does not work). - `<mailto:küche@tf.de>` works as well. A quick note on standards: from a quick read I understand that basic SMTP does not allow non-ascii characters in addresses. SMTPUTF8 (RFC6531 through RFC6533) adds this but is only from around 2012 and thus quite new (atleast for an internet standard). TL;DR: While this is annoying I expect that the workarounds are sufficient for us.

kerem commented

2026-03-07 20:08:16 +03:00

Author

Owner

@DavidAnson commented on GitHub (May 16, 2024):

Great, thank you for the update!

@DavidAnson commented on GitHub (May 16, 2024): Great, thank you for the update!