Just to confirm: The shortening of “mae” to “ma” is a common southernism - I don’t think you’ll hear it in the north at all. Mae will always be understood everywhere, and I’ve never been misunderstood using “ma”.
The only point to note for those preferring “mae” is that “he is”, taught as “ma fe” on the southern course, is mae e (no f) if you use mae. It’s a tiny point, and no-one wil complain / misunderstand etc if you say mae e, it’s just a bit more difficult to say, and sounds a tiny touch uncofortable to my ear.