Both Eegee and tape3950 have 1 posts on the forums. Therefore they are in the new user's group until they have at least 2 approved posts. People in the new user's group has less permissions, therefore they can't PM or email other users. This is why you are not seeing the envelope icon.
We discussed at SketchUcation this feature and now we set the "Users can contact me by e-mail" option off by default for newly registered members and set everybody's setting off. So if somebody would like to enable others to email him/her, he / she has to permit it by turning "Users can contact me by e-mail" on.