[Dovecot] Allow INBOX to be shared, sigh... fixes #594

data/conf/dovecot/dovecot.conf

@@ -23,6 +23,7 @@ ssl_dh_parameters_length = 2048
 log_timestamp = "%Y-%m-%d %H:%M:%S "
 recipient_delimiter = +
 auth_master_user_separator = *
+mail_shared_explicit_inbox = yes
 mail_prefetch_count = 30
 passdb {
   driver = passwd-file