ORDB.ORG blacklist is closed, RBL checks against it will always return 'LISTED'
In some cases we are seeing this problem, which is not related to TZO but which we are documenting for your convenience. The problem is bounced or rejected email, indicating the sender server is "blocked by ORDB.ORG".
The answer in this case is ORDB.ORG does not exist any longer. See DNSBL.COM blog entry on ORDB: http://www.dnsbl.com/2007/02/status-of-relaysordborg-dead.html.
TZO does not use ORDB.ORG for any of it's RBL checks.
Please NOTE: If TZO mail servers attempt to deliver to a recipient's mailserver - and that mailserver is broken (rejecting all email) - there is no way for TZO to bypass the server's rejection. TZO is obligated to REJECT the incoming message.
With regard to rejections, the TZO mailservers will ALWAYS 'quote' the recipient mailservers response text. In some cases the recipient's rejection is helpful:
550 - Listed at ORDB.ORG
...but in some cases it is not as helpful, and may cryptically state:
550 - blocked - spam site
. The recipient domain wholly determines how helpful and specific the rejection message might be.
If the recipient's rejection is this vague, then the problem becomes a 'black box'. More information can only be discovered if the recipient's Administrator checks their server logs to see why they rejected it.
This demonstrates the importance of Whitelisting mailserver connections from TZO, if you use TZO Store And Forward (SAF) or Spam and Virus Filter (SVF) to deliver your email. TZO FAQ #353 describes the TZO IP address 'ranges' which should be whitelisted. This step will eliminate inadvertent email delays, blockage or rejections.
