Problème d'envoi de messages

Bonjour,

je n'arrive pas à envoyer des messages à l'adresse banita@sfr.fr de ma messagerie professionnelle dont le nom de domaine est sucborotou.ci

mon DNS public est 83.229.88.30
message de retour d'envoi de mail à banita@sfr.fr:
The attached message had PERMANENT fatal delivery errors!

After one or more unsuccessful delivery attempts the attached message has been removed from the mail queue on this server. The number and frequency of delivery attempts are determined by local configuration parameters.

YOUR MESSAGE WAS NOT DELIVERED TO ONE OR MORE RECIPIENTS!

Failed address: banita@sfr.fr

--- Session Transcript ---
Fri 2012-11-23 07:50:42: Parsing Message <xxxxxxxxxxxxxxxxxx\pd10000207258.msg>
Fri 2012-11-23 07:50:42: From: bertrand@sucborotou.ci Fri 2012-11-23
07:50:42: To: banita@sfr.fr Fri 2012-11-23 07:50:42: Subject:
=?iso-8859-1?Q?TR:_ALG_:_Fiche_=22Pr=EAt_de_manuels_scolaires=22?=
Fri 2012-11-23 07:50:42: Message-ID: <001401cdc94f$231c29a0$69547ce0$@ci>
Fri 2012-11-23 07:50:42: MX-record resolution of [sfr.fr] in progress (DNS
Server: 83.229.88.30)...
Fri 2012-11-23 07:50:43: P=010 D=sfr.fr TTL=(452) MX=[smtp-in.sfr.fr] Fri
2012-11-23 07:50:43: Attempting MX: P=010 D=sfr.fr TTL=(452) MX=[smtp-in.sfr.fr] Fri 2012-11-23 07:50:43: Attempting SMTP connection to [smtp-in.sfr.fr : 25] Fri 2012-11-23 07:50:43: A-record resolution of [smtp-in.sfr.fr] in progress (DNS Server: 83.229.88.30)...
Fri 2012-11-23 07:50:44: D=smtp-in.sfr.fr TTL=(60) A=[93.17.128.25] Fri
2012-11-23 07:50:44: Attempting SMTP connection to [93.17.128.25 : 25] Fri
2012-11-23 07:50:44: Waiting for socket connection...
Fri 2012-11-23 07:50:45: Socket connection established (192.168.50.1 : 3407
-> 93.17.128.25 : 25) Fri 2012-11-23 07:50:45: Waiting for protocol
initiation...
Fri 2012-11-23 07:50:49: <-- 554 5.7.1 Client host rejected: cannot find your reverse hostname, [83.229.14.66]