Unrelated to anything, but... There are many fax vendors (sfax for example), that provide "virtual fax machines", and that email you received faxes. Those email

Unrelated to anything, but... There are many fax vendors (sfax for example), that provide "virtual fax machines", and that email you received faxes. Those emails could get lost. The fax service could lose the data. Just because a fax was received by a "fax machine", doesn't necessarily mean someone actually got it. Certified mail is probably a better "someone received it" option, if that is the desired requirement.