When we view an email that we sent to a customer and the HubSpot sidebar loads, it almost always lists three contacts:
1) The from address that we sent the email from. This should be filtered out since it adds no value.
2) The customer's email. This is the one we really want to see.
3) The HubSpot BCC email address that we use to log emails in HubSpot. This should be filtered out since it adds no value.
In conclusion, the HubSpot sidebar should filter out contacts that are configured as FROM email addresses in Missive. It should also filter out HubSpot BCC email addresses.