(Suppose you applied the following formula in D column)
=RIGHT(A2,LEN(A2)-SEARCH("@",A2))
Now to the next of D column you can write following formula to separate specific ESP
=if(d2=”gmail.com”,”Gmail”,if(d2=”live.com”,”Live”,if(d2=”hotmail.com”,”Hotmail”,if(d2=”yahoo.com”,”Yahoo”,if(d2=”aol”,”Aol”)))))