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My emails to recipients with a Email Security Gateway keep getting blocked! What do I do?

  • Type: Knowledgebase
  • Date changed: 10 months ago
Solution #00001879

Scope:
This solution applies to senders whose emails are consistently blocked by a Email Security Gateway.

Answer:
First, determine why the messages are being blocked. Examine the bounce (NDR) message that was received indicating the failed delivery for more information as to why the message was blocked. Below is a short list of reasons that may be contained within the bounce message and their meaning:
  • Sender address rejected: Blocked indicates that either the sender's email address, or domain has been added to the Barracuda's customizable blocklist.
  • Client host rejected: Blocked indicates that the sender's public IP address has been added to the Barracuda's customizable blocklist.
  • Recipient address rejected: Blocked indicates that the recipient's email address has been added to the Barracuda's customizable blocklist.
  • Message content rejected, UBE indicates that the content of the message was recognized as spam.
The Email Security Gateway also has the capability to query public RBL lists. The public IP address of the sending mail server may have been blacklisted by one of the public RBLs. To confirm if this is the case, use the Spam Database Lookup utility provided on www.dnsstuff.com to check the mail server's public IP address against a list of public RBL servers. If the IP address has been blacklisted, then the administrator of that server should contact the RBL that has listed the IP address for more information on why it was added, and what steps need to be taken to get removed.

Link to This Page:
https://campus.barracuda.com/solution/50160000000GWZ9AAO