Hello,
Sorry to hear that you're having errors logging into RoundCube. I attempted to create a test email account on your domain and also encountered the SERVICE CURRENTLY NOT AVAILABLE! Error No. [800] error when trying to login to RoundCube.
It looks like Horde and SquirrelMail are still working without any issues, and you should be able to still connect to the server with a normal mail client. I'll go ahead and let our system administration team know about the issues with RoundCube and they should be resolved shortly.
Sorry again for the inconvenience.
- Jacob