With the help of Frank Steurich from Supportteam All-inkl and http://kasapi.kasserver.de/
See Github https://github.com/grzchr15/kasapi-soap-client for SOAP services for https://www.kasserver.com
Ar http://www.bretterhofer.at/blog/projects/autoconfiguration-thunderbird-for-domains-served-from-allinkl-com i show my atempts to used that SOAP services to make Autoconfiguration Thunderbird happen.
Feel free to fork and