Hello Serge,
I think the ability you are talking about was moved over to a per-brand setting. Go to Settings-> Brands -> YourBrand -> Portal Options tab -> Display option to send ticket list by email in portal . I believe there is a bug right now (i just fixed it and it will be in the next version) that it is reversed. So you will need to un-check it for it to show up in the portal when the user clicks the tickets icon. There will be a button to the right under Actions that says Email All My Tickets. Note: upon upgrading on our next release you will need to check this back to keep it showing.