I've tried to look at the other threads but there don't seem to be any definite solutions.
Three of us are using Hubspot in our small company. For two of us, the emails are being logged when sent through Outlook.
The other colleague's emails are being logged, even though the BCC is populated with the correct hubspot bcc address. We have no do-not-log domains or addresses, and his address is definitely a valid user address.