Click Whitelisting
Click whitelisting is a false-positive avoidance system.
When enabled it provides a clickable link in most SMTP rejection messages which should appear in any bounce messages received by a sender when their mail is rejected by TUXGUARD Mail Gateway.
It allows them to whitelist themselves by clicking the link and solving a Google ReCAPTCHA, after which they can resend their message and it will be accepted.
To enable it you must register with Google ReCAPTCHA and register a new site to get the Site Key (Public Key) and a Secret Key (Private Key).
Note
Click whitelisting uses a web server embedded into the SMTP server running on TCP port 3000, so to use it you must open port 3000/tcp to all worker nodes. It runs on the worker nodes and Click whitelisting uses the Shared Cache to store the whitelist keys.
Enabled
Toggles Click Whitelisting on or off.
You must enter a Secret, Private Key and Public Key for the feature to start working regardless if this is enabled or not.
Secret
To prevent someone from abusing the Click Whitelist a secret is used to prevent tampering with the click data which is entered into the Cache
Private Key
The site key as provided by Google ReCAPTCHA.
Public Key
The secret key as provided by Google ReCAPTCHA.
Initial TTL
How long (in seconds) should the Click Whitelist key be valid for.
The default is 604800 (7 days). This is to prevent whitelist keys from being used long after the rejection was first sent.
Whitelist TTL
How long (in seconds) should a whitelist key be valid for after a message is successfullyreceived.
The default is 3456000 seconds (40 days). Provided that a message is successfullyreceived from the whitelisted sender, then the whitelist key will be refreshed to this value, soprovided at least one successful message is sent within this time, the whitelist entry will not expire.