Gandi.net Groups

Hello,
after having opened a Gandi mail accout with success, I am trying to set
a specific signature as the standard template for sending all mails from
this box. 
I have succeeded in doing so, except for some graphic elements found in
the signature, which show up with a frame and a red cross when a mail
is prepared to be sent. 

Currently the images refered to in the signature are posted as web
images located on a server outside Gandi. May  be thi si the problem,
and we should import the images within Gandi borders. 

May be the way to get the graphic signature rieght is completelty
different. 

Can someone help?

Thanks in advance.