OpenVPN Support Forum

The underlying user database that phpbb uses is LDAP. Quoting the phpbb administrator control panel (General -> Authentication):

LDAP e-mail attribute: mail

Set this to the name of your user entry e-mail attribute (if one exists) in order to automatically set the e-mail address for new users. Leaving this empty results in empty e-mail address for users who log in for the first time.

So phpbb does not check for updates to the LDAP mail attribute: you need to change the email in phpbb instead. phpbb.

I think this is reasonable behavior, because it allows defaulting to the email address in LDAP, but does not prevent customizing the email address per-service. In fact, this is the same behavior as we have in Trac now.

Samuli