SRFAX Seems to be working fine with a Mac
After unsuccessfully trying Ring Central (can't use a 800 number as your reference phone number on the cover sheet, bogus and weird and I find that out after an hour with tech support which involved them forcing me into letting them take control of my computer (I could kick myself for that). Their solution after all of this ...don't use a cover sheet! Also they make you download some piece of software for the Mac where lot of the links would go to webpages with error messages further making their whole thing more confusing.
And trustfax couldn't upload any pdf's AT ALL kept claiming it was over 5 mb and they were all under 500 kb and no customer support to help.
So just tried SRFax and it seems to work just fine. Really simple can upload a logo for the coversheet and use our company's 800 phone number on it, imagine that. I just need to send and receive a few faxes (maybe 20) every month so the $6.95 service will do me just fine (I think it allows 150). They have other options too for higher volume. Anyway, it was the only one of the three that worked right out of the box without having to contact them or look at their support page, etc. Great simple interface very straightforward. They have a 14 day trial so no risk. And they even have a "cancel account" easily accessible in the user section which is not true for trustfax. With Ring Central it took me about 10 minutes to cancel via the phone we will see if they both bill me anyway.
I'll let you know if this one dissappoints but so far so good. Yeah Finally.... I hope.