Mail APP

Is there any alternative application available for web mail. ( alternative for hord)

There are various groupware apps in the app center. They all offer very good web mail clients.
You can probably also install Roundcube (check php requirements first), but there is no app available for that, so you’d have to configure it yourself.

is that groupware apps are opensource?

The groupwares source code is open, but the licenses of the apps may require you to buy a maintenance contract. Please search for “groupware” here: … p-catalog/

There is a how-to for installing Roundcube on UCS here: … _Roundcube