Check if an email from GMX is phishing and report it

Have you received a suspicious email that appears to be from GMX (e.g. ‘GMX Customer Service’ as the sender's name) and in which you are asked to take action related to your GMX account? It is possible that this is not a legitimate email from GMX, but Phishing, a fraud attempt to obtain your personal data.

This service allows you to have such emails checked for authenticity and report them if they are not trustworthy. To do this, you must upload the email to be checked in EML or MSG format. You will then receive direct feedback based on an automated check. The maximum file size is 8 MiB.

How can an email be saved in MSG or EML format?