resolve 
resolve @
resolve @@
resolve @a.
resolve @..
resolve @.@.
resolve !
resolve a!
resolve !b
resolve a!b
resolve !@
resolve a!@
resolve !b@
resolve a!b@
resolve %
resolve a%
resolve %b
resolve a%b
resolve %@
resolve a%@
resolve %b@
resolve @@
resolve a@@
resolve @b@
resolve a@b@
resolve a%b@
resolve a%b@MYHOSTNAME
resolve a!b@MYHOSTNAME
resolve a@b@MYHOSTNAME
resolve a[b]@MYHOSTNAME@MYHOSTNAME
resolve a[b]%MYHOSTNAME@MYHOSTNAME
resolve a[b]%MYHOSTNAME%MYHOSTNAME
resolve MYHOSTNAME!a[b]@MYHOSTNAME
resolve MYHOSTNAME!a[b]%MYHOSTNAME
resolve MYHOSTNAME!MYHOSTNAME!a[b]
resolve user@dom.ain1@dom.ain2
resolve user%dom.ain1@dom.ain2
resolve dom.ain1!user@dom.ain2
resolve user@[1.2.3.4]@dom.ain2
resolve user%[1.2.3.4]@dom.ain2
resolve [1.2.3.4]!user@dom.ain2
resolve user@localhost.MYDOMAIN
resolve user@[321.1.2.3]
resolve user@1.2.3
resolve user@host:port
resolve user@host
resolve user@host
verify user@host
verify user@host