"Mailto" URLs are not correctly parsed to mail composer window. The html code of such a link looks like this:
<pre>
pmx-auto-approve%2b5a4e6f41105a88cafa36c8e6e513aadb@gate02.hof-university.de?subject=Release%20message%20from%20quarantine&body=%5b%23iMQ-1%5d
</pre>

Clicking this link with a "fat" mail client results in a reply message with correctly formated recipient, subject and body. (successfully tested with outlook, thunderbird, Android Mail, iOS6 mail)
When selecting the link in sogo, the fields are malformed. For example the string "pmx-auto-approve" is missing completely in recipient field, the body is empty and the body text is also shown in to field as part of the (incomplete) recipient address.
Please see attached screenshot...