You are sending faxes to one or more FaxMaker Online numbers, but it doesn't work. The numbers seem reachable, but the transmission of faxes doesn't work. It tries to initiate the fax but after a few seconds, the transmission ends.
Support agents can check in the Concord portal, that for the customer's FaxMaker Online fax numbers, the failure to send is seen with a
Not a fax machine error. When calling these fax numbers, a fax tone is heard, which indicates that there is an actual fax machine behind the numbers.
If there is call forwarding/call redirection involved, then the backend Server team is generally unable to effectively support the remote call forwarding/call redirection and for German fax numbers, this is entirely unsupported.
Open a Support request with all the numbers to which you are unable to send the faxes. These numbers should be the ones where you are not able to send the direct faxes and information related to the telecommunications carrier that tried to deliver the fax. Also, provide contact information related to one or more senders' numbers from where the fax cannot be sent along with the senders' fax number/carrier
The Support team will get back to you after working with the backend Server team and let you know about the status/fix for the same.
Support agents should escalate this issue to the Concord team with the numbers mentioned by the customer and let the Concord team know if there are any routing changes to the destination numbers required from the backend to fix this.