I just install new version of roundcube:
Installing Roundcube 0.8.1 (Stable)
And find that Cyrillic addresses which work with early version, now not work!
Even written with punycode...
On some way, address was stripped:
Sorry, I couldn't find any host named xn----8sbncyg3cbfh.xn. (#5.1.2)
Regards!