Undelivered Mail Returned to Sender

[moe]

Hi,

i have an nabble-account for a few month.
today i subscribed one mailinglist but every time i answer
to message i so get the following error.

<[e-mail]>: host
    mail.sourceforge.net[66.35.250.206] said: 550-Postmaster verification
    failed while checking <[e-mail]> 550-Called:   213.203.199.121
    550-Sent:     RCPT TO:<[e-mail]> 550-Response: 550 5.1.1
    <[e-mail]>: Recipient address rejected: User unknown in
    virtual alias table 550-Several RFCs state that you are required to have a
    postmaster 550-mailbox for each mail domain. This host does not accept mail
    550-from domains whose servers reject the postmaster address. 550 Sender
    verify failed (in reply to RCPT TO command)

But my senders-adress is sure the same as i have in my nabble-account.
So why will my messages bounced ?

btw: i dont send with [e-mail] ;-))

moe

[Will L <Nabble>]

I checked and your Nabble posts seem to have all been ok.

moe wrote:

...So why will my messages bounced ?...

Can you point me to the posts that are bounced?

[moe]

it was a problem with my mailserver (its solved)
... sorry

Moe