Adresse bizarre

Bonjour,
lorsque je veux consulter ma messagerie et que je dois taper mon identification,je trouve en plus de mon adresse mail ,une aute adresse que voici,

misshanamontana@yahoo.fr

mais cette adresse n existe pas ??

This is the mail system at host msfrf1101.sfr.fr.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

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The mail system

<misshanamontana@yahoo.fr>: host f.mx.mail.yahoo.com[98.137.54.237] said: 554
delivery error: dd This user doesn't have a yahoo.fr account
(misshanamontana@yahoo.fr) [0] - mta143.mail.sp2.yahoo.com (in reply to end
of DATA command)

voilà ce que je reçois si j envoie un mail ?
qui peut me renseigner ?
Merci