This could happen due to a problem with the fax server configuration or with the fax cards on the fax server.
To research a missing fax, perform these steps:
Verify the fax phone number. Ask the subscriber to resend the fax to confirm that the problem was not with the receiving station or with an incorrect fax phone number.
In the fax server administration program, look for the fax in the outbound queue. If the fax is there, continue with step 3. If the fax is not there, verify the configuration of the fax gateway, make changes as necessary and resend the fax.
Confirm that the fax server is configured correctly for the fax cards that are installed:
If the server is not configured correctly, make changes as necessary and resend the fax.
If the server is configured correctly, the problem is most likely with the fax cards.
To resolve all other third-party fax integration problems with Cisco Unity, refer to these documents: