Hi, Lets Encrypt released IDN support 1 month ago. Is it supported by ISPconfig 3.1? I tried but it didn't work. Thanks in advance!
I'm not aware of any problems, ispconfig passes the idn domains (IDN encoded as they are stored in the databse) to LE in the same way than normal domains, so it should work.
Use the debug mode to see which domains (and their encoding) were passed to letsencrypt by ispconfig and check the letsencrypt log.