LinkedIn launched LinkedIn Intro app for iOS to show LI profiles right inside the native iPhone mail client. The downside it that LinkedIn have to access the content of users emails to implement this feature and also can manage the user’s passwords for his email accounts on other providers. Even, LinkedIn also accesses to the contents of users iOS calendars, notes and call-in numbers, which they then transmitted in plain text, not encrypted. The company claims that the process is totally secure and that all user data including credentials and email are not permanently stored.”]
Source: http://securityaffairs.co/wordpress/19100/hacking/linkedin-intro-intercept-emails.html