[Numpy-discussion] Mail delivery failed: returning message to sender

[Mail Delivery System]

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  numpy-discussion at lists.sourceforge.net
    SMTP error from remote mailer after RCPT TO:<numpy-discussion at lists.sourceforge.net>:
    host mail.sourceforge.net [66.35.250.206]: 451-Could not complete sender verify callout
    451-Could not complete sender verify callout for
    451-<numpy-discussion at lists.sourceforge.net>.
    451-The mail server(s) for the domain may be temporarily unreachable, or
    451-they may be permanently unreachable from this server. In the latter case,
    451-you need to change the address or create an MX record for its domain
    451-if it is : retry timeout exceeded

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