You turn on the eMarketeer integration from your settings page as an admin.

Once integrated to eMarketeer, all events such as mail opens, clicks, form answers etc are sent to Leadexplorer and matched to companies and leads with the same domain name.

This means when looking at a company in Leadexplorer you can also see all interactions any contact on the same domain did in eMarketeer.

You will also see all eMarketeer contacts from the matching domain (based on email address) on the company card in Leadexplorer.