How to configure EXM to create new messages with a custom language version, as default - sitecore

Question

I am trying to configure the EXM root for an Austrian website to create the new messages with a de-AT language version and to have the de-AT language selected as default.
My question is: How can I configure EXM to automatically create a language version for de-AT when a new message is created?
What I've done so far ..
I managed to achieve having the de-AT selected automatically by playing around with the Language - Select the target language field from the Message Context section of the Standard fields - but the actual message item that is created does not contain the de-AT version - and I am getting an error when trying to save the message.
Error message: Edited language version 'German (Austria)' could not be found. It may have been deleted by another user.
As it can be seen in this screnshot, when I open EXM and I create a new message, the de-AT language version is automatically selected. The problem is that the message has no de-AT language version assigned, so it won't allow to save the item.

Answer 1

I think you missed to add language version to standard values of your message template.
Templates in EXM works in a same way as anywhere in Sitecore. You should have language versions for your emails under:
/sitecore/templates/Email Campaign/Messages
/sitecore/templates/Branches/Email Campaign/Messages

Answer 2

None of the 'tricks' worked to automatically add a new language version when you create a new message inside EXM, therefore I've added a new OnItemSave event which checks if the Item is derived from the base Message template and creates a new language version - based on the own business logic.
Config:
<configuration xmlns:x="http://www.sitecore.net/xmlconfig/">
<sitecore>
<events>
<event name="item:added">
<handler type="ABC.SitecoreExtensions.Handlers.EmailExperienceExtensions, ABC" method="OnItemAdded" />
</event>
</events>
</sitecore>
Code
namespace ABC.SitecoreExtensions.Handlers
{
class EmailExperienceExtensions
{
readonly Sitecore.Data.Database masterDb = Sitecore.Configuration.Factory.GetDatabase("master");
private const string EXM_BASE_EMAIL_TEMPLATE_ID = "{A0EA9681-5C86-43AB-80F7-C522DADF6F12}";
public void OnItemAdded(object sender, EventArgs args)
{
Assert.ArgumentNotNull((object)args, "args");
Item obj1 = Event.ExtractParameter(args, 0) as Item;
if (obj1 == null)
return;
if (obj1.IsDerived(new Sitecore.Data.ID(EXM_BASE_EMAIL_TEMPLATE_ID )))
{
//logic to determine the context site and to pickup the language
....
if (rootItem == null)
{
return;
}
var siteContext = SiteContext.GetSite(rootItem.Name);
var lang = LanguageManager.GetLanguage(siteContext.Language);
Item ca = masterDb.GetItem(obj1.Paths.FullPath, lang);
using (new Sitecore.SecurityModel.SecurityDisabler())
{
try
{
if (0 == ca.Versions.Count)
{
ca.Versions.AddVersion();
}
}
catch (Exception ex)
{
// catch exception
}
}
}
}
}
}