Faxing is a huge part of my setup and I added export variables to ensure t38 support at every leg of the fax call using FusionPBX/Freeswitch both incoming and outgoing. Combine this with a Netgen ATA and it is as reliable as POTS and WILL use t38 whenever the other end supports it. Although Bandwidth does not advertise it, I have gotten t38 calls on incoming faxes since my DIDs are through Bandwidth. It is still used for medical and legal where email addresses are deliberately not listed. I am seeing more and more instances where the sensitive document can be uploaded via their website so I don't have to use fax as much as I did before.