Full Example Error Message: 
Error occurred on sending fax the length of the value is 1, but the required minimum is 5. Organization ID: 00DA0000000xEufAAE Organization Fax Number: 8662234444 Fax SFID: a1W4R55550JoDtGUAV

The reason this error could occur: 
Not using the direct dial format format to send a fax to recipient. The dial out format should be XXX-XXX-XXXX (example: 866-822-1234). Do not need to include country code if dialing fax numbers within USA since the A5 Fax server is in USA. If you are dialing from your USA fax number to an international fax number outside USA, dial out format should be 011+Country Code+Fax Number.

To resolve:
You will need to send another fax with the proper dial out format to ensure it can be processed and sent to end recipient.