Schulte RBL issued incorrect Blacklist warnings

This morning we received a few notices from our Free/Paid Monitoring users that they were listed on the Schulte RBL, but when they used our Free Blacklist Lookup Tool they were not listed there. We just visited the Schulte RBL website this morning to see if they had any reported problems yesterday and they have posted this warning:

2009-02-27 note

Late last night a DNS server configuration error on one of the
authoritative DNS servers for caused a temporary
error in RBL blacklisting status data for all queries to this
particular DNS server. The problem was identified and resolved
as soon as I was made aware of it. No new bad DNS data should be
served from this machine. However, remote servers may cache this

If you continue to have problems with this RBL listing your IP, please contact us at with your IP and domain name and we can manually update your account.

MxToolBox is not affiliated with any Blacklists, we just provide a public tool that can be utilized to see if you are on a Blacklist. If you are on a Blacklist, rest assured as we do offer Blacklist Protection! For more information please feel free to visit our website or email us at

We’re always looking for new Blacklists to add, so if you want to suggest one to us, please send an email to

For information about other Blacklists that have shut down or Blacklists that are having problems, view this forum post.

3 thoughts on “Schulte RBL issued incorrect Blacklist warnings

  1. Mac

    I tried to contact you, using the e-mail address you provided, and it just leads to further rejection of my e-mail (see note below), so how can I even bring the problem to you attention so you can “mannually correct” the problem as you stated you would? Catch 22 at work or is it a game with your fellows?
    The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was ‘’. Subject ‘Rejected IP address problem’, Account: ‘’, Server: ‘’, Protocol: SMTP, Server Response: ‘550 [PERMFAIL] destination not valid within DNS’, Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79


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