Error:
Error occurred on sending fax
Request content length (38237546) has exceeded our 30MB ceiling Organization ID: 00D6000XXXXXXX Organization Fax Number: 866-XXX-XXXX Fax SFID: a2I0e000001DaRCEA0

Reply:
You may see this error message if trying to send an outbound fax for a file that is over 30 MB. The limit on file size within eFax platform system for outbound is 30MB so you would need to send a fax with a lower file size.