as I wrote on Ticket 8941 the HEX representation does not work correctly. With version 22.214.171.124 it looks better, but not correctly. The following example shows the problem.
and the result is
something linke: thisd;isd;ad;test@exad;ple.cf;d;
Maybe the problem is that the "mailto:" tag is also encoded. If you put the code in Firefox ist works.