GuiFax E-mail to Fax Service is an Internet fax solution that allows an unlimited number of users to send faxes directly from their e-mail, simply by addressing an e-mail message to the recipient's fax number. Users can attach most document types to their messages. E-mail to fax automatically converts the e-mail message and its attachments into a fax, and instantly delivers it to the recipient.
Frequently Asked Questions
This is a list of the most frequent questions asked about GuiFax.
Click here to view FAQ
If you still have questions. Please use the below form to send an email to
Click here to email support
The following file types are support by GuiFax Internet Fax Service...
TXT, PDF, DOC, DOCX, XLS, XLSX, RTF, PPT, PPTX, and TIFF (Fax-formatted)
You may also send almost any other type of file by simply converting it to a PDF using free program such as CutePDF or Bullzip PDF.
E-mail to Fax Troubleshooting
Should you receive a failure, you will receive a bounce-back e-mail that includes a reason for the failure. Here are some of the reasons as to why this may have occurred.
- Incorrectly configured/missing SPF record.
- GuiFax checks for a valid SPF record on every E-mail to Fax attempt in order to prevent spam/fraud.
- Sender is not authorized by GuiFax.
- If you are trying to send an E-mail to Fax attempt from an e-mail address that is not registered with GuiFax, you your fax fill fail and be abandoned
- To remedy this, follow the steps to register an e-mail address.
- The call was unable to negotiate T38. Error Received : T38_NEG_ERROR
- This usually occurs when the call did not properly negotiate the T38 protocol, which is necessary for faxing using our E-mail to Fax service. You may want to try dialing the destination number from a handset phone to check if you are receiving fax tones. If you are, and the E-mail to Fax still fails, try opening a ticket with Support and provide the call to, call from, and time of call.
- The outbound call failed.
- If your E-mail to Fax attempt fails with “Outgoing call failed”, check to verify that the destination is a valid/working number. After verifying this and checking for fax tones, open a ticket with Support if any issues persist.
- Attachment file is the wrong format
- You may see this error if the file you are trying to attach is not the correct format. The supported file types are:
- TXT, PDF, DOC, DOCX, XLS, XLSX, RTF, PPT, PPTX, and TIFF (Fax-formatted)
- If you are still having issues with your file, you may want to convert it using a program such as CutePDF or BullzipPDF.