I don't think it's free as you already paid for it and its included in your monthly service fee. It's like saying Onesuite has a free incoming fax service but I have to pay $1/month. Even though it's only $1/month, it is still not free. I am paying $1 a month for unlimited incoming fax service. Cheap but not free.
Don't know if the signup was free. Either way, many virtual phones also provide a certain amount of faxes for free. If you're doing business, $20 a year or $5 a month for something like these items is reasonable to have and usually expected these days.
I agree. I always get confirmation from Onesuite whether the fax was successful or not and I believe most online fax service does the same thing.