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:

  den@lfloors.co.za
    host mail.lfloors.co.za [129.232.138.143]
    SMTP error from remote mail server after RCPT TO:<den@lfloors.co.za>:
    550 Unroutable address
  dempsterl@mweb.co.za
    host securemail-mx3.synaq.com [196.35.198.130]
    SMTP error from remote mail server after RCPT TO:<dempsterl@mweb.co.za>:
    550-rejected because 52.221.55.32 is in a black list at combined.abusix.dnsbl
    550 https://lookup.abusix.com/search?q=52.221.55.32
  dempsey@mweb.co.za
    host securemail-mx3.synaq.com [196.35.198.130]
    SMTP error from remote mail server after RCPT TO:<dempsey@mweb.co.za>:
    550-rejected because 52.221.55.32 is in a black list at combined.abusix.dnsbl
    550 https://lookup.abusix.com/search?q=52.221.55.32
  dempster@unpcs1.cs.unp.ac.za
    all hosts for 'unpcs1.cs.unp.ac.za' have been failing for a long time (and retry time not reached)