Hi Ericx thanks a lot for your answer.
Well if i use a fixed string between the <PARAM> tag, the POST works fine.
Also, according to the whitepaper, it should be
<param name="PARAM">${prop.Username}</param>
But this raises the following javascript error.
Error: obj has no properties
Source File:
http://server/zimbra/js/ZimbraMail_a...v=070115194221
Line: 1312