LPS-45724 - Partial backport of LPS-39591 (Fix Mail Portlet after migration to Alloy 2.0) on master (43d0ad478d99e646cd61a10472b51c043588b26e) for 6.1.x because we need the HTML and CSS from Bootstrap
LPS-45724 - The receivers (To, Cc, BCc) list goes beyond portlet limits (boundaries) in Mail Portlet