snom ONE supports T.38 in two ways.
First, it connects devices that are talking the T.38 standard. If you Fax machine is connected to analog terminal adapter (ATA) that supports T.38 and your PSTN gateway also supports T.38, then the PBX will attempt to pass the signals through. While there is no guarantee that this will work flawlessly, there is a reasonable chance that you will be able to continue printing out paper when someone on the other side wants you to do that. Second, the snom ONE mailbox can listen to the Fax tone. When it detects a Fax message, it starts to use the T.38 protocol and converts the incoming Fax into an email that is sent to the owner of the mailbox, just like it has just received a voicemail. Because the PBX may have a mailbox for each user, this may eliminate the step to sort incoming Fax messages and it avoids time when dealing with paper.
When using the Fax2Email feature you will have to configure you Email Settings on the system.
NOTE: It's best not to use the redirection cell phone feature when using the fax setting.
When your email is up and running assign your email address on the Extension Level On the users extension Email settings make sure Send message as attachment is set.
If you extension has a DID you can start receiving faxes simply set your mailbox setting to FAX, this setting will not play the voice mail message instead it will play the CNG tone after the transmission as finish it will then send the user a PDF file VIA email. You can also choose to enable the voice mail as well but it's prefer to use the default setting or 1-5 seconds under the " Time until mailbox picks up"
After the transmission is done snom one will send you an email with the attached PDF file shown here.
Here is a sample PDF file faxed to the snom one server.
To set your Auto Attendant to receive incoming fax check this article on Auto Attendant.
—To redirect fax messages to a specific destination, you can use the direct destination “F”. The CNG tone that announces a fax tone is recognized by the system and is translated into the “F” key.