I wish I had gotten this message before your friend confronted her, I would have had some advice on how he could have had some fun with her.
1. He could have just never mentioned the email, and if she asked pretend he didn't get it, and either continue on as before OR continue on for a few days, and if she didn't break up with him, break up with her (again not mentioning email). Deny her closure.
2. He could have just stone walled her, don't answer her calls, don't hang with her, politely ignore her, and have no time to talk to her. . . and again not mentioning the email and maybe even denying its existance . . . Again denying her closure.
3. He could have immediately replied saying thank god! He was hoping she would break up with him because he has wanted to break up with her for like months now and didn't want to hurt her feelings. He could cite the reason as just not really liking her, none of his friends thinking she was worthy i.e looks and personality (they just felt sorry for her), and not thinking she was long-term material. And he has met all these cute girls he has wanted to see but has felt bad and by the way is her better-looking-than-her-girlfriend still free and would she hook them up? Can't we be friends? And then start killing her with kindness.
4. Thank her for breaking up with him because of course she isn't good looking enough to take to his formal but he would be obligated to take her.
Before everyone just thinks this is mean, remember, if you break up by email you are demonstrating the height of immaturity and insecurity . . . And I am not going to even touch on the AOl IM thing . . . that's just downright cruel .. .
IF a guy did that he would be dateless for the rest of his life . . . women would be posting hate posters about him in Cosmo and other magazines. . .