So I found a solution to my problem. I just added a span
tag in the add_submenu_page() hook and it work:
add_submenu_page(
# The slug for the parent menu page to which this sub menu belongs
'email-service',
# The text that't rendered in the browser title bar
'Breaking News Email',
# The text to be rendered in the menu
'<span class="breaking-news-toggle">Breaking News Email</span>',
# the capability required to access this menu item
'send_email',
# The slug by which this sub menu is identified
'my-email-service',
# the function used to display the options for this menu's page
array(&$this, 'email_service_form')
);