Document information

Document ID: 4621
Subject: Email Challenge Response
Creation date: 12/14/15 4:35 PM
Last modified on: 8/15/18 2:33 PM

Email Challenge/Response

Challenge/Response filtering, also known as auto-white-listing, or permission based email is increasingly popular and controversial mechanism to prevent spam. Though it can be extremely effective, it has drawbacks.

Consider the following scenario that explains this mechanism.
  • Bob sends an email message to Mary
  • Mary's email server accepts the message but before transferring it to her Inbox, the server sends a message back to Bob, confirming if he actually sent a message. Bob must reply to this automatically generated message which confirms his original message.
  • Since spammers almost always either forge the sender or send from invalid address. Therefore, Mary will never get the message is someone else pretends to be Bob.

Enabling Challenge/Response in Xeams

Follow the steps below to enable Challenge/Response in Xeams.
  • Log in to Admin Console
  • Click Server Configuration
  • Select the Challenge Response tab
  • Check Enable Challenge Response, specify an email for processing and a threshold value. Check the help in Admin Console for the exact description of each field.
  • Click the Save button

Disadvantages of using Challenge/Response

  • It is considered rude by many users
  • It is not a viable option if you receive emails from unknown individuals, such as potential clients
  • Slows down email delivery
  • Will never work if both parties use a Challenge/Response system

Customizing Challenge Email

The template for the email message sent during challenge/response comes from $INSTALL_DIR\config\CResponse.txt. Modify the contents of this file to change the text for this email.

User comments

Posted by Bob on 5/4/21 11:52 AM

If Mary emails me first her platform had better whitelist me or I will write a rule to reject her CRS

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