I have noticed a problem with adding character encoded mailto links to the core contact form.

The following encoded mailto link:

<a href="&#x6D;&#x61;&#x69;&#x6C;&#116;&#x6F;:&#105;&#110;&#x66;&#111;&#64;&#x65;&#x78;&#97;&#x6D;&#x70;&#108;&#101;&#x2E;&#99;&#111;&#x6D;">&#105;&#110;&#x66;&#111;&#64;&#x65;&#x78;&#97;&#x6D;&#x70;&#108;&#101;&#x2E;&#99;&#111;&#x6D;</a>

...is converted to:

<a href="mailto:info@example.com">&#105;&#110;&#x66;&#111;&#64;&#x65;&#x78;&#97;&#x6D;&#x70;&#108;&#101;&#x2E;&#99;&#111;&#x6D;</a>

*** Please view the source of this page to see the encoded characters. ***

I have a block on my front page that has an encoded mailto link in it and it doesn't decode the mailto link as above. I think drupal may be filtering the mailto and decoding it on the way to the browser.

I have checked the above with drupal 4.7 and 5.1.