No. Tern's email is built for relationship email with your travelers and contacts, not for bulk marketing or mailing-list campaigns. There is no campaign or mass-send tool.
You can still email more than one person at once. Add multiple recipients, use CC and BCC when you've connected your email inbox, and choose whether everyone shares one thread or each person gets their own with Send separately. This is meant for individual and small-group emails tied to your trips and contacts.
Email campaigns are currently available to a limited group of users as we continue to refine the experience. We plan to expand access in the future. Tern's email integration is designed for individual or small group emails — for large-scale marketing sends, we recommend using a dedicated email marketing platform.