If VOIPo would add FAX OUT it would be worth it.
It's been added.

I was with microfax for a couple of years before they were bought out by fax.com. Then I became a fax.com customer. When I switched to voipo they offered me a couple of months free with efax.

Faxes come through fine. Very satisfied here.

Regarding security, I've not given it much thought. Although I receive important documents, they are not particularly sensitive.