The mailing list for listmasters using Sympa

[Steve Shipway <address@concealed>]

Are your lists configured to add a header or footer?  This can cause some 
changes to the MIME type.  If Outlook 2010 is sending in Mime 
multipart/alternative then it mights append to the text part or do nothing; 
if your Outlook 2011 is sending in ms/tnef format you might end up with a 
mime/multipart containing the tnef and text.  Not sure what it will do then.

Try removing any defined headers/footers and see if it continues to do this.

Steve

Steve Shipway
University of Auckland ITS
UNIX Systems Design Lead
address@concealed
Ph: +64 9 373 7599 ext 86487