Email replies to a message sent through a connected email inbox will be logged in your CRM automatically. When you receive a reply to an email that was not previously logged, or a new email from a client or contact, you can log it in HubSpot manually using your forwarding CRM email address.
Replies to emails will be logged automatically on the contact's timeline if you have connected your inbox and the following is true:
If you send an email from your connected inbox, but you do not select the Log checkbox when sending the message, this email will not log to your CRM and therefore, subsequent replies to that email will not log. However, the replies can be forwarded to the CRM using your forwarding address.
If a reply comes from another email address to your thread, and this email address is not an existing contact, the reply will not log to your CRM.
An example is when an email is sent to contacts@domain.com (an existing contact) but a reply comes from contacts-alias@domain.com (not a contact).
However, the replies can be forwarded to the CRM using your forwarding address and you can opt to merge the two contact records.
HubSpot traces related replies in the Inbox folder only through the inbox connection. The reply must be in the main Inbox folder, not in a child folder or an entirely separate folder. If a reply email is moved to a separate folder because of filtering rules, the reply will likely not log to the CRM.
If an email thread starts with your shared inbox in the conversations tool, you cannot switch to reply using your personal connected inbox mid-thread. The replies will not continue to log to HubSpot because this will create a new thread that HubSpot cannot detect.
If you change inbox providers while you still have active threads using your previous email address, email replies will stop logging to HubSpot. In addition, if you're using sequences, contacts who are currently enrolled in a sequence will not be automatically unenrolled because HubSpot can no longer detect the replies. Reconnect your inbox using the correct provider to successfully log replies.