email bookmark missing from left hand side

When I turned the laptop on this morning the email tab on the left hand side of the page had disappeared (along with all my e-mails) and I cant find it! (Been through help and all the menu options).  I still have tabs for contacts, tasks and calendar.  Please help! I currently can’t view any e-mails!

If there are no tabs at all move cursor to lower left and  right click   if menu opens select the items tabs you want shown.
If you have at least one tab showing then cursor goes on that and right click

Thank you so much! thought there would probably be a simple fix but couldn’t work it out.

Just a reminder   always backup your emclient  using the emclient backup on some schedule basis and know where it is putting the files