Inbound Faxing Errors when using Diverted Numbers

Note:  Using diversions on fax to e-mail numbers is not supported.

When using a diverted number for your inbound faxing, you may experience an unusually high number of errors and failures.  This applies to any kind of redirection, including exchange-based redirection and VoIP redirection from 3rd party providers.


These errors may include but are not limited to:

  • The call dropped prematurely
  • Various negotiation errors
  • Protocol errors


The issue is caused by the increased latency introduced into the call channel by a diversion.  Faxing is a very latency-sensitive technology and the extra few hundred milliseconds of delay introduced by a diversion can completely break the negotiation and communication process.

For this reason, we do not support using diverted numbers for faxing.



There are two possible resolutions to these issues:

  1. Port the diverted number to us, so it can be attached directly to your Fax to e-mail service (removing the latency)
  2. Discontinue using the original/diverted number and use the direct number associated with the service instead (the number you were diverting to)



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