Apache Reference: mod_auth_anon, Anonymous_MustGiveEmail

Anonymous_MustGiveEmail

Specify Whether a Real E-mail Address must Be Given as the Password
Syntax: Anonymous_MustGiveEmail on|off
Example: Anonymous_MustGiveEmail off
Since: Apache 1.1

This directive specifies whether the user must give a real e-mail address (``user@domain'') as the password on anonymous logins. Blank passwords are then prohibited.