Users unable to unsibscribe via UI

Users should be able to cancel all of their subscription via navigation, from 'My account'. Relying only on the unsubscribe links in the body of emails is not enough for many reasons:
- various international privacy regulations require an environment where users are able to unsubscribe easily through the UI interface of the web-site that signed them up.
- the emails may be lost;
- access to the mailbox may be lost or temporarily unavailable;
- mail client software may have trouble showing or following the links in the emails;
- the emails may become undeliverable due to filter settings or other issues.

In other words - users MUST be able to unsubscribe through the web site. Currently there are no user- accessible menu items that would allow them to unsubscribe.

Additionally, this path:
$items[] = array(
'path' => 'autoresponder/unsubscribe',
'access' => TRUE,
'callback' => 'autoresponder_user_unsubscribe',
'type' => MENU_CALLBACK
);

displays an Access Denied page...