CloudFax - Error Messages

If you encounter an error message when sending your eFax, please reference the error messages below for further guidance.

Note: If you still need help after reviewing the error messages below, please contact the DoIT Help Desk for further assistance.


"Busy" Indicates that the called number (phone line) is already in use or engaged.

Exceeded ECM Retransmit

“Exceeded ECM Retransmit” indicates the call was answered by a fax device and connected using ECM or Error Correction Mode. Due to poor line quality or a poor connection for that specific call attempt the transmission of the fax required an excessive amount of data to be retransmitted to the receiving device to get acknowledgment of successful reception of the fax, the call was aborted to allow a retry or new attempt to get a better connection and to ensure the call duration did not ensure excessive overtime charges.

Fast Busy

“Fast Busy" indicates that there was no available path to the attempted fax number. This normally indicates that the destination is currently overloaded, or that there is an outage with the specific number or in the area attempted such as that due to a fibre cut. This can also be caused by severe weather conditions in the area of the destination. In most cases Fast Busy conditions are temporary, please verify the fax number you’re trying to reach is valid and if so please try again later.

General Error

"General Error" indicates that another uncommon error not listed above has occurred resulting in the failure to transmit your fax. Please retry the fax job or recipient again. If you get the same error again please contact Concord customer service for further assistance and investigation.

Invalid Attachment

“Invalid Attachment“ indicates the attachment is not one of the file types listed below, The document should be converted into a supported format and resubmitted.

  • .TIF/TIFF (Tagged Image File Format)
  • .TXT (Plain Text)
  • .RTF (Rich Text Format)
  • .DOC, DOCX (Microsoft Word Windows v.97, 2000, XP, 2003, 2007, 2010)
  • .XLS, XLSX (Microsoft Excel Windows v.97, 2000, XP, 2003, 2007, 2010)
  • .PPT, PPTX (Microsoft PowerPoint Windows v.97, 2000, XP, 2003, 2007, 2010)
  • .PDF (Adobe Portable Document Format)
  • .HTML (Hypertext Markup Language)
  • .JPG, VSD (Visio and JPEG)
  • .GIF (Graphics Interchange Format)
  • .PNG (Portable Network Graphic)

Invalid Fax Number

“Invalid Fax Number“ indicates a problem with the destination fax number. You must address the email-to-fax request with the full fax number, including area code, that you wish to fax with no spaces or punctuation. Please correct the fax number and try again.

Job Cancelled

“Job Cancelled“ indicates that the job or recipient number was cancelled or the set time for delivery expired.

Negotiation Failed

“Negotiation Failed” indicates the call was answered by a fax device but during the initial training phase of the call, communication between the fax transmitter and the receiving fax device failed or the two devices could not agree on the parameters to be used for the call. This often indicates a phone line quality issue and may occur at the beginning of the fax transmission, or, during the fax transmission between pages on a multi‐page fax.

No Answer

"No Answer" indicates that the line was not picked up (answered) by a fax machine or person before timing out. The timeout is sufficient to ensure at a minimum of 5‐ 8 standard rings, which is actually duration of 55 seconds.

No Attachment

“No Attachment” Indicates that there was no document attached to the email-to-fax request. You must attach the document you wish to fax in an accepted format, such as .DOC or .PDF. Please see for a comprehensive list of acceptable file types.

Not a Fax Machine

"Not a fax machine" indicates that a fax device has failed to answer the call. Specifically, fax tones or the fax signal from a remote machine has not been detected. This may for a number of reason including but not limited to, a wrong number, a machine not configured to automatically answer, or a device that has stopped answering because it is out of paper or has a paper jam.

Sit‐Tone / Operator Msg

“Sit‐Tone / Operator Msg“ indicates that the call was intercepted by the special situation information tones followed by an operator message, examples include "The number you have dialed is disconnected or is no longer in service. Please check the listing and try your call again.", "The number you have dialed has been changed…the new number is…XXX‐XXX‐XXXX", "All circuits are currently busy, please try your call again later". "Operator Msg" indicates the same issue however the special situation information tones were not detected.

Transmission Failed

“Transmission Failed“ indicates the receiving fax machine has answered and connected but the fax was not able to be fully and successfully transmitted. This can be caused by line quality issues, fax device issues, the sharing of phone line with other devices such as credit card processing terminals. Temporary conditions such as severe weather conditions in the destination area can also cause transmissions failures.

Unauthorized Sending Address

“Unauthorized Sending Address“ indicates that the email address from which the email-to-fax request was sent is not registered with Concord. The origin email address must be added as a valid sender via the Concord Web Portal. Please login to the Concord Web Portal to add the email address. If you are unable to do so or need instruction with this process please contact Concord customer service for assistance.

Voice Answer

"Voice Answer" indicates that either a person or voicemail message answered the call.

Invalid Email Address

"Invalid Email Address" indicates that you are not setup to use the CloudFax service. Request access to the CloudFax service here. Please note, once you've been added to the CloudFax service, your access can take approximately 1 business day to go into effect.


You can download the list of error messages as a pdf to place near your multi-function printer here:

See Also:

Keywords:cloud fax error messages concord efax not working concordfax support email mfp cloudfax invalid email address busy exceeded ecm retransmit fast busy general error invalid attachment invalid fax number job cancelled negotiation failed no answer no attachment not a fax machine sit-tone operator msg transmission failed unauthorized sending address voice answer   Doc ID:97483
Owner:Christina G.Group:DoIT Help Desk
Created:2020-01-29 18:09 CDTUpdated:2020-05-04 19:28 CDT
Sites:DoIT Help Desk, Office 365
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