What the others already said.
In our situation, most colleagues mainly use HubSpot to keep customer related emails logged. Thus, the Outlook/Office365 add-ins are used. For most customers there are few problems, as we usually have one deal going for each customer. But then we have some distributors, and here everything goes crazy. Especially since emails not related to any deal are showing up in sales deals. I have until recently assumed that our users were doing something wrong, but now I understand that the problem is in how HubSpot is handling emails and associations.
Please at least make the auto-association an option and only require associationbetween email and contact.
Kjell