Windows Server 2008 - Mail Gönderme Sorunu

Elimle bir e-posta adresine mail gönderebiliyorum. Ama SMF sistemli forum siteme biri üye olduğunda, biri özel mesaj gönderdiğinde falan mesajlar otomatik olarak gitmiyor. Verdiği iki üç çeşit hata var buyrun:

        Recipient: [SMTP:[email protected]]

        Reason: Remote SMTP Server Returned: 550 Requested action not taken: mailbox unavailable 

MailEnable: Message could not be delivered to some recipients.
The following recipient(s) could not be reached:

        Recipient: [SMTP:[email protected]]
        Reason: Remote SMTP Server Returned: 550 Requested action not taken: mailbox unavailable

Message headers follow: 

 Bunu uzun zamandır almıyorum: 

MailEnable: Message delivery has been delayed.

Message is waiting at home for delivery to 199.59.243.108.

The message will be retried for another 30 hours.

Reason: Mail Server for windwoslive.com could not be contacted at this time. MailEnable will keep trying to deliver this message and will notify you of any progress.

 Bunuda uzun zamandır almıyorum:

  MailEnable: Message Delivery Failure.

Reason: ME-E0193: [395578B1A02A4D55A5CD55FFA7B65EF0.MAI] Message Delivery Failure.

Your message addressed to the target domain (gmx.de) could not be delivered because the mail server responsible for this domain returned a permanent error.

The server returned:

554-gmx.net (mxgmx011) Nemesis ESMTP Service not available