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["X-Term" <address@concealed>]

Hi all

After using Sympa 3.0.3 with no problems for almost a month, I've been 
receiving some error messages from postfix this last week :

I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.

For further assistance, please contact <address@concealed>

If you do so, please include this problem report. You can
delete your own text from the message returned below.

                        The Postfix program

<address@concealed>: mail forwarding loop for address@concealed

This mail is being returned to the sender, and in my logs I see the same 
error :

Mar  2 09:23:51 mail postfix/local[25413]: E0CDF7F81F: 
to=<address@concealed>, relay=local, delay=9, status=bounced (mail 
forwarding loop for address@concealed)

Anyone knows why could this be happening ?