Hi Manuel,
The LinkedIn connector isn't actually based on the email (though Facebook, Twitter, etc., is). With LinkedIn we need an exact match between the first name, last name, and company name with the LinkedIn profile and the Lead or Contact record. You'll also need to confirm that the profile isn't private. You can click the blue refresh arrow on the right of the profile to re-try a connection if nothing is pulling in automatically.
Please let me know if you have any questions!