Examples Using 'host'

Which DNS server(s) serves the domain 'yahoo.com' ?
host -t ns yahoo.com.

The same query, using one of the root name servers:
host -t ns yahoo.com. a.root-servers.net.

Which mail server(s) handles incoming mail for 'walla.co.il' ?
host -t mx walla.co.il.

What is the email address of walla's mail exchange server?
host -t a messaging.walla.co.il.