I set up the plugin with all the default settings (including reverse text). Worked nicely in every other browser, but for some reason in IE9, e-mail address had two letters in the wrong order. Like this:
firstname.lastname@example.org became email@example.com
The mailto-link in question was working properly. Just those two letters appeared in the wrong order. Not a big problem, I just disabled text reverse and everything else is working fine.