We construct a regex pattern that exactly matches any one of the target items by combining them using the alternation operator (|) and anchoring the pattern with ^ and $. Special characters (like +, ., /, -, $, commas, etc.) are escaped as needed so that the items are matched literally. This ensures that only and exactly the provided target strings are matched and nothing else. For example, 'john.doe+filter@example.com' becomes 'john\.doe\+filter@example\.com' in the pattern, and similarly for the other items. The final regex is a non-capturing group that alternates between the exact strings, ensuring all rules are met.