Switched onto email, excited (9)
I believe the answer is:
emotional
'excited' is the definition.
(emotional can mean very excited)
'switched onto email' is the wordplay.
'switched' indicates anagramming the letters (letters switch places).
'onto'+'email'='ontoemail'
'ontoemail' with letters rearranged gives 'EMOTIONAL'.
(Other definitions for emotional that I've seen before include "Deeply feeling" , "Arousing intense feelings" , "Impassioned - excitable" , "Dramatic" , "Passionate" .)