Why do some classmates have the "Send This Person A Message" and others do not.
The classmates that have the "Send This Person A Message" have completed their profile on the classmates page. This allows individuals to send this person an email but email address in never shown on the web site.
If I enter my information on the Classmate page, can people see my phone number and e-mail address?
No one other than a few committee member can see this information. If someone sends you an e-mail by clicking on "send this person a message", at your picture, they do not see your e-mail address either. Only if you respond do they see your e-mail address. The information is private.