When sending an email, senders may sometimes be required to confirm that they are real people. To do this, we offer two types of CAPTCHA: Word cloud and Puzzle.
Our recommendation is to favor the CAPTCHA Puzzle, as it offers better protection against automated submissions while remaining simple for legitimate senders to complete.
What is the difference between "Word Cloud" and "Puzzle"?
CAPTCHA Word cloud
The sender must read a word displayed in an image and copy it.
This validation is based primarily on text recognition.
CAPTCHA Puzzle
The sender must drag a piece (using a slider) to place it in the correct position.
Validation relies on interaction and signals that make automation much more difficult.
The CAPTCHA Puzzle is best suited when you want to prevent automated attempts to send unwanted emails.
Specifically, it allows:
Better resistance to bots and automated scripts.
A reduction in the volume of attempts, typical of spam campaigns.
More robust protection against circumvention methods (for example, those that can automatically "read" a word).
Result: legitimate senders are validated and their messages are delivered, while automated attempts have a much harder time getting through.
Is the CAPTCHA Puzzle more restrictive for the sender?
The puzzle may take a few seconds longer than a word cloud because it requires dragging and dropping.
In practice, this is still quick for a human, and this slight extra effort significantly improves protection against automated submissions.