> I don’t currently and haven’t previously used the Imported Contact feature

But perhaps the others did? If 'Steve Jacobs' imported his contacts and you exchanged emails with him, LinkedIn apparently becomes aware of that relationship. In fact:

> Tami has a total of 5 connections, lives in Seattle, no public company or title listed, but we just happened to exchange a few emails a couple days prior regarding some questions I had about software her company sold.

Tami probably used the imported contacts feature here, and that's how LinkedIn would know.