New emails from existing contact aren't in hubspot

[#1]

Hy, I'm been testing Hubspot  for some weeks and I have a (big) problem. 

I imported all contacts. When I send them an mail, no problem: Huspot  tracks my mail

But when a contact of mine sends a new email (not an answer, a new mail, for example for a new quote)   , my  Hubspot doesnt import this mail in hubspot  system.  So: 

1. the contact is existing
2. if I send mail to the contact it's all ok. 
3. If the contact send me a new mail, (not an answer to mail of mine)  that mail isn't

How could I do?

[#2]

Hi @denisevalerio,

New incoming emails that are not associated with responses are not expected to log in HubSpot. The only tool that pulls in incoming emails is the conversations inbox tool.

Thank you,
Jenny