Inside a pipeline record, under the Emails tab, you can also switch between the "All emails of the contact" view and "Emails linked to this pipeline record", just in case you need it. 

To associate an email with a particular deal, hover over the email subject and click the link button. A list of deals associated with the contact will be displayed; choose the deal to which you want to link the email.

Once you link an email to a deal, a new icon will be displayed next to the email, indicating the association. You can always unlink the email or link it to another deal.

Automatic linking process:

1. Sending mail via Bigin:
   
1. When an email reply originates from a pipeline record within Bigin, it will automatically associate with that specific pipeline record.
2. Receiving emails:
   
1. If a contact holds a single open pipeline record in Bigin, the email will link to that respective pipeline record.
   
2. For contacts with multiple open pipeline records, the email will link to the most recently modified pipeline record.
   
3. In cases where the contact previously had a Closed-Lost pipeline record, the email will not link to any pipeline record but will remain stored within the contact's email-related list.