Laravel Mail via campaign monitor smtp error

I am using a business campaign monitor account to try send Laravel Mail.

Config:

MAIL_DRIVER=smtp
MAIL_HOST=smtp.api.createsend.com
MAIL_PORT=587
MAIL_USERNAME=<token>
MAIL_PASSWORD=<same token>
MAIL_ENCRYPTION=tls

I created the token in the CM transactional page, and am getting the error

" {"exception":"[object] (Swift_TransportException(code: 550): Expected response code 250 but got code \"550\", with message \"550 5.7.22 no valid dkim found
\" at /Sites/dashboard/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:419)

via Chebli Mohamed