Start by installing the application here.
Sending Mail from the HubSpot CRM
After you have installed the HubSpot integration, DocuPost cards will appear in the right sidebar for every contact or company record. You may need to scroll down to see the cards, and you may re-arrange them if you wish.
Click the "Send new letter", "Send new check" or "Send new postcard" button to begin the process of sending mail from HubSpot.
Note that your contact or companies first name, last name, address, city, state and zip will be automatically filled in, if this information is available for the record.
Automatically Sending Mail from Workflows
To create automations that send letters or postcards, create or navigate to a Contact or Company-based Workflow in HubSpot.
When adding a new action, you will find "Send postcard by U.S. mail" and "Send letter by U.S. mail" options under the DocuPost heading. Select one of these options to configure your mailing.