The idea is that Firefox isn’t the only responsible here, there is also out mighty Google which collect data about safe and unsafe sites and send the database updates right to Firefox center.
As Stated by Mozilla The company forbids the collection of this data by Mozilla or its partners for any purpose other than improvement of the Phishing and Malware Protection feature.
Firefox People said it’s Google’s side problem.
Looks like Google thought that GMX are redirecting in an insecure way that phishing sites are taking advantage of.
But GMX Team Said about there dereferers
The dereferencing is done due to several technical and legal requirements, but rest assured that it is not done in order to gather information.
If you’ve noticed, a lot of information is placed in the URL when you’re accessing GMX via the webmail portal. Not using a dereferer and clicking on a link within an email would practically send information in the URL to the linked site as well. Even though this information cannot really be used by anyone else but GMX, it’s still possible that others would take advantage of it to gain access to GMX accounts. To prevent this, all links are re-packed in a dereferer and sent without the URL information.
More info on dereferers on this site:
http://dereferer.org/info.asp
Hope some one can clear this mess.