I'm using the feature "a different domain per language". All domain names are pointing to the same wp installation. It works fine to pick the right language for a certain domain, and even to default to english (which is my default language) for a number of domains such as .ie, co.uk, co.za, .com.
But now I would like to have two different domains showing Spanish language, .es and .mx. As far as I can see it's only possible to map one domain to one language. Is it possible to work around this?
You should add a new language to add a new domain. For example if you want to add the domain "es" and "mx", you can add a new language "Spanish Mexico", for example, and duplicate the content of Spanish for this "new language".
To add a new domain, click on the WPML > Languages. Click on the "Edit languages" link and click on the "Add Language" button.
Then you can add the new domain in WPML > Languages > Language URL format.
Please let me know if you are satisfied with my answer and if I can help you with any other questions you might have.