How to read a text after "Email:" via stream reader without looping ...

StreamReader reader = new StreamReader(Target1);
            string line = string.Empty;

            var matches1 = Regex.Match('Email', ('^.*')).Groups[1].Value;
            while ((line = reader.ReadToEnd().ToLower()) != null)
            {
                if (line.Contains('email'))
                {
                    string[] crefids3 = line.Split(':');
                    for (int mj = 0; mj < crefids3.Length; mj++)
                    {
                        randomName = crefids3[1].ToString();
                    }
                }
            }
            reader.Close();