You can set up a signature, which will be used for all emails you send through HubSpot.
Instructions to set up or update your signature:
1. Click your HubSpot Account (Company) Name in the upper right corner.
2. Click Profile & Preferences
3. Scroll down to CRM Communication | Signature, then click Edit Signature
4. In the pop-up box, add or edit your email signature, including text, links, and images
5. Click Save