I just moved my resume etc. from QXP 6.5 to InDesign CS2. In the header, I have my email address with a hyperlink defined as "mailto:firstname.lastname@example.org".
I used Q2ID to tanslate the Quark doc, , but I recreated the hyperlinks, as they were not translated by the plug-in.
When activating the link in a InDesign generated PDF, the resulting address = "email@example.com"--everything before the underscore character (including the underscore) is ignored. All other addresses work fine.