Wrong encoding from iPhone?

Hi, we have a groupwise 2012SP1 with Datasync 2.5.299 and the email receive in my groupwise client from an iPhone (using Datasync) has the wrong encoding for the accents.

If I change the display to text only all the accents are OK!
I've attached a TEXT.htm from groupwise, if I open it in IE it show ok, but in Groupwise it display like this:

Bonjour Éric,
Si tu n'as pas reçu les iPhones demain à midi, SVP, tÃCopyrightCopyrightphoner à M. CÃŽtÃCopyright de U2B Telecom pour avoir le statut de la commande.


instead of:
Bonjour Éric,
Si tu n'as pas reçu les iPhones demain à midi, SVP, téléphoner à M. Côté de U2B Telecom pour avoir le statut de la commande.


It seems to be only from iPhone, I tested from a Samsung Galaxy and its ok.

Does someone know what to check?
thank you
Eric.
text.zip