Challenge/Response filtering, also called auto-white-listing, or permission based email is increasingly popular and controversial mechanism to prevent spam. Though it can be extremely effective, it has draw-backs.
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 Xeam
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
Posted by Bart on 9/18/15 8:05 AM
there is any change to make customize the challenge message ?
or it can be done by editing some files ?
I agree that being able to customize the challenge message would be very helpful. It will allow me to briefly explain the need and apologize for the inconvenience. I can also add an alternative such as a phone number to call and be quickly whitelisted.
Posted by Chris Worall on 11/1/13 8:43 PM
Why not give us the option to customise the text that gets sent out. We might be able to word it to sound less rude!
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