Using the xwiki.xWiki.sendMessage function does not work correctly, becomes JunkMail due to std Outlook configuration

When using the sendMessage call, all details are provided to the sendMessage function, including the To: field (as per the API).
Looking at the headers, it looks like a rarely-used field ("for") is used instead of the To: field; the result is that the message is sent to the user, but the To: field is blank (so it looks like a group spam email).
A standard installation of Outlook 2003 will then treat the email as JunkMail, and accordingly removing it from the user's sight into the little-known Junk E-Mail folder.

• • This was last tested in 0.9.840; which sends the to: header correctly.