Introduction

3CX includes a fax server that allows you to receive faxes in PDF format and forward them to one or more extensions. 3CX Fax Server is based on the T.38 standard protocol and requires a compatible supported T.38 VoIP gateway or provider.

To receive faxes, you must configure a line or a DID to be dedicated for receiving faxes, so that all calls on this number are forwarded to the 3CX Fax Server. The 3CX Fax Server will then receive the fax, convert it to PDF and email the fax to the configured email address.

3CX Phone System includes a pre-configured fax extension (ext: 888). This extension is used by the 3CX Fax Server for incoming fax calls, which will then be routed to an email address. In addition, the 3CX Phone System can be configured to proxy fax calls (T.38 traffic) to a fax machine connected to an ATA or another software based T.38 fax server, by creating an additional fax extension.

Fax Server Configuration

To configure fax reception:

1. In the 3CX Management Console, go to “Settings” > “FAX Server.”
2. Enter an email address to forward the faxes received on this number.
3. Select the fax extension that should receive incoming faxes. You can use the default built-in ‘888’ extension.
4. Assign one or more available DIDs to the fax server.
5. Click “OK” to save. Your fax server is now configured!

Configuring fax machines / fax servers

You can connect a fax machine or a fax server to 3CX using a supported ATA (Analog Telephone Adapter). To do this you need to create a FAX extension in “Advanced” > “FAX”:

1. Click “Add” to add a new fax machine.
2. Specify the Extension Number, Authentication ID and Password, as well as the Default Caller ID.
3. Click “OK” to save and configure using a supported ATA.

Reference:

https://www.3cx.com/docs/manual/fax-server/