1. There's a after credit scene at episode 22, make sure you don't miss it
2. I'm sure you will realize it eventually, but just to be clear with one concept. Kurisu survive in the future that Suzuha told them does not mean what you think it means. Different worldlines lead to different future, Kurisu surviving in the current worldline and her death in the original worldline are two different future. In order to save Mayuri, Okabe was trying to undo all the Dmails and shift to the original worldline where he saw Kurisu died. So the future Suzuha told them won't apply there
2018-08-06 21:37:41 +0000 UTC
the first d-mail: okabe sent daru a text message about the murder and at that time darus phone was hooked up to the microwave so instead of him receiving it at the time of okabe sending it, daru received it a week earlier.