Transactional emails are used to send content which facilitates an already agreed-upon transaction or updates a customer about an ongoing transaction. This might be an update about an order that has been placed by your customer, or a to send a record of purchase, or other email correspondence of that nature.
Are you sure?
When setting an email to “Transactional/Relationship,” you’ll get a prompt to make sure you understand what is good practice when sending transactional type emails.
You should always review the CAN-SPAM laws before sending transactional emails.
Go to Campaigns and choose the campaign you wish to make transactional.
Then to Settings > Footer Settings
Then, you’ll see the “Primary Purpose” setting. Change it to “Transactional” in the drop-down.
Go to the broadcast Settings > scroll down until you see the "Primary Purpose" setting.
Go to Settings > Primary Purpose in your one-off email.