I don't think there is any commercially available software, that I know of, that will do this. I did write my own homegrown program, but, it's only about 60% accurate. Basically, you have to have a database of "key words", and, what you want them changed to. "(space)Llc(space)" to "(space)LLC(space), "Aaa" to "AAA", "Ibm" to "IBM", Jlb Lawn Svc" to "JLB Lawn Svc.,etc.
Problem is no matter how many key words you come up with, there will always be some that gets missed. After you run the program, you have to browse the file, then add the ones it missed to your key word database.
After a couple of years, I finally abandoned the whole dang thing, and, convinced the client that, if you want it done right, with 100% accuracy, then, the company names (along with the mailing addresses) need to be all in upper case (which, is what the USPS really wants anyway). He finally agreed, and, for the last several years, we've had no problems.
Hope this helps!