sap pi mail receiver adapter greek charset in attachment

Hi,

I would like to set as an attachment ( .csv) the PI content with encoding  ISO-8859-7 in mail ( mail receiver adapter).
I have set the mail package checkbox based on SAP Note 748024 (Content-Type: text/plain; charset=ISO-8859-7)  but  when i open the csv with excel the encoding is UTF-8 and not ISO-8859-7.  I also tried to do an xslt mapping , passing the encoding in the xml content but this did not worked out.
Please let me know if you have any tip.

Regards
Antonis