Fully agree, except revealing the email should be enabled by the member.

The team captain should be able to communicate with his members using email, but the member should first accept it.

In the profile, there is an "Information" check box to authorize email communication by WCG, another box should be added to allow communication from the team captain.

This box should be in the profile, and should also be presented just above the "join this team" button.

the default value for this box should be either disabled, or set the same as the "information" field.

The use of a robust, open source mail list program such as MailMan would be a great tool for team captains ...