Step 1: Cook the Macaroni: Bring a large pot of salted water to a boil. Add the macaroni and cook according to package directions until al dente. Drain the macaroni and rinse it under cold water to stop the cooking process. Allow the macaroni to cool completely.
Step 2: Prepare the Dressing: In a large bowl, whisk together the mayonnaise, sweet pickle relish, yellow mustard, white vinegar, granulated sugar, salt, and black pepper until smooth.
Step 3: Combine Ingredients: Add the cooled macaroni, diced celery, red onion, red bell pepper, and chopped hard-boiled eggs to the bowl with the dressing. Gently stir to combine until all ingredients are evenly coated.
Step 4: Chill and Serve: Cover the bowl with plastic wrap and refrigerate for at least 2 hours, or preferably overnight, to allow the flavors to meld. Before serving, stir the macaroni salad and adjust seasonings to taste. Serve cold.
Optional Tips and Substitutions: For a tangier salad, add an extra tablespoon of white vinegar or lemon juice. For a sweeter salad, increase the amount of sugar to taste. Diced ham or cooked bacon can be added for a savory twist. Feel free to substitute the vegetables with your preferred choices, such as green bell pepper, carrots, or green onions.