Combine mayonnaise, pickle relish, mustard, white vinegar, sugar, paprika, onion powder, and garlic powder in a bowl. Stir until fully smooth with no dry spice pockets or mustard streaks.
Rest
Refrigerate for at least 30 minutes before serving. Overnight is strongly preferred — the flavors settle and the sauce improves significantly.
Notes
Keeps in an airtight jar in the refrigerator for up to 1 week.
Do not freeze — mayo-based sauces break when frozen.