In a content, go into a rich-text, type an email address like test@ametys.org then go to next line (Enter).
Automatically, a mailto link is created.
If you try to edit this link as : test@anyware-services.com, the CMS says : "Vous devez saisir une adresse internet valide"

After an analyze, the regex used for this field is : /^https?:\/\/[^\s]+$/
It should be extend to mailto and tel links.