Mostly this question arises if you are using English proofreading software. Mostly if it’s advantageous then great, but the disadvantages can outweigh the adanatages.  Many a times software will fail in catching up all the mistaken words or show an irrelevant synonym.

A professional proofreader person will check for any spelling mistakes in the given document first.   Then for any punctuation errors and also for poorly presented text on the page if any. All of this is done by turning on a special feature in MS Word called ‘Track Changes’.