c# regex how to match user's input to an array of words/phrases

I have an array with different words and phrases. The user will input a spam message and I'm supposed to check whether there are any matches to the words and phrases already in the array. For each match the score will +1 and if the score is more than 5 then the possibility of it being a spam message is Yes.

My score doesn't increase though and I'm not sure why.

string[] spam = new string[] {"-different words and phrases provided by programmer"};

        Console.Write("Key in an email message: ");
        string email = Console.ReadLine();
        int score = 0;

        string pattern = "^\\[a-zA-Z]";
        Regex expression = new Regex(pattern);
        var regexp = new System.Text.RegularExpressions.Regex(pattern);

        if (!regexp.IsMatch(email))
        {
            score += 1;
        }