Talk:Steins;Gate (visual novel)/Walkthrough/@comment-184.59.38.245-20140412102057/@comment-148.100.135.216-20140413055432

All mails are contained within the chapters. A mail from chapter 2 won't arrive in chapter 3.

Now about your problem: Did you get the achievement Cruel Sister? And if so, did you remember to reply to that mail?