in my board people don´t see the real email adresses of other users. They can only send mails through the board. There is no need to hide the "email"-buttons. The magic trick could be done in includes/usercp_email.php But unfortunately I am not so good in php and mySQL.
Imagine a simple query done in usercp_email.php: If recipient of the email has the sender of the mail in his ignore list, then message_die. Else send email.
As I said I am not able to code that by myself. But I am sure that it could be done in includes/usercp_email.php. I know that because I have installed the following mod:
## MOD Title: Minimum Posts Before PM and Email Allowed
## MOD Author: Merlin Sythove < N/A > (Merlin Sythove) n/a
## MOD Author: azw < N/A > (Art Zoller Wagner) http://www.DigitalDesign.us
## MOD Description: Sets a minimum of posts required before
## users can send PM or emails to other members.
## Admins and mods are excluded; they can send PM and emails immediately.
## Also replying to a PM is allowed even if user has not yet posted.
## Settings can be changed in Admin Control Panel
## MOD Version: 1.0.2
You can find this short mod here: http://www.phpbb.com/phpBB/viewtopic.php?t=397453
Greetings from Austria