Manage your emails and phone calls - don't let them manage you. Ideally check at planned times, and avoid continuous notification of incoming emails.

The more senior you are the more selective you need to be about when to be available to receive phone calls.

Try to minimise the time that you are available to take unplanned phone calls, unless you are in a customer-facing, reactive role (customers can be internal too).

Even if you are customer-facing, plan some time-slots when you are not available, or you'll never get anything important and pro-active done.