How LinkedIn snuck Intro info into emails on iOS

LinkedIn is boasting about rolling out its new feature for mobile after facing obstacles from Google and Apple.

Part of LinkedIn's new effort to enhance its mobile presence is through the use of technology it got when it acquired Rapportive in February 2012. Wit the technology, the company has found a creative way to get past the barriers that block plugins from infiltrating user emails on iOS.

The new feature is called Intro, and basically uses Rapportive's technology to insert a banner into emails that show LinkedIn information about the person who sent them. So, users who get an email from a stranger can see the information that person has listed on LinkedIn without navigating away from the email. Part of the hope for LinkedIn is that users will see this information and navigate away from the email to the sender's LinkedIn profile. Another unintended benefit for the site is that people who haven't updated their LinkedIn profiles in a while may rush back to the site to spruce up their presence before it starts showing up in every email they send.

How this was accomplished seems pretty interesting, though. Rapportive's technology was once a Gmail plugin, but was banned from Gmail after a Google redesign. Making things even more difficult is that Apple's Mail app for iOS does not support plugins or extensions at all.

So LinkedIn built an API that "extends" the iOS mail app, as it described in this blog post. Using a proxy server that speaks the IMAP protocol that most email providers employ, Intro tacks the banner featuring the sender's LinkedIn information onto the top of the message while the message is being forwarded from the device to the email provider. In this process, it also recognizes the specific device used to open it, and adapts its banner to meet its requirements. 

Then, using a CSS code response that is native on the mobile version of Safari, LinkedIn was able to make the Intro bar interactive, meaning users can click on it to find out more information about the sender.

The blog post goes into a lot of detail on the project, and the team is not exactly modest about the accomplishment, calling the task "impossible" several times throughout. But it is some impressive work.

The response so far has been mixed. Buzzfeed tech reporter John Herrman immediately pointed to LinkedIn's history of data security issues, and he has a point. Intro is likely to encounter backlash from privacy advocates. Meanwhile, TechCrunch's John Constine gushed about the feature, promising that "once you install it, you’ll automatically become a daily LinkedIn 'user' even if you never visit the professional network itself."

Image via LinkedIn blog

Join the Network World communities on Facebook and LinkedIn to comment on topics that are top of mind.
Must read: 10 new UI features coming to Windows 10