When I published a part of a SIP message the first time, I wondered why a part of SIP URIs where shown as 'mailto' link.
After some research I found that there is a 'Email Cloaking' plug-in which detects email addresses (This email address is being protected from spambots. You need JavaScript enabled to view it.) and hides them in the HTML code against email harvesting robots.
A Java script makes the email address visible again and formats them even as 'mailto' link.
This behavior disturbs in technical texts and can be disabled in the Plugin Manager under content 'Content - Email Cloaking'.