We are using SendGrid Marketing Email API for pushing newsletters to our subscribers, and wish to include a custom list-unsubscribe header in each of the emails. However I cannot see any API method supporting adding headers to the message. Am I completely blind or are there just no methods for adding custom headers to SendGrid emails?
Thank you Brgds Lukas
You can add custom header via their Web API with the header argument (must be in valid JSON format without integers), as described in their doc:
POST: https://api.sendgrid.com/api/mail.send.json
POST Data:
api_user=your_sendgrid_username&api_key=your_sendgrid_password&to=destination@example.com&toname=Destination&subject=Example_Subject&text=testingtextbody&from=info@domain.com&header={"List-Unsubscribe": "unsubscribe_email@your_domain"}