public class CustomSubmitAction : SubmitActionBase<string>
    {
        private FormSubmitContext _formSubmitContext;
        public CustomSubmitAction(ISubmitActionData submitActionData) : base(submitActionData)
        {
        }
        protected override bool Execute(string data, FormSubmitContext formSubmitContext)
        {

        try
        {
            this._formSubmitContext = formSubmitContext;
            var nameFieldValue = GetValue(this._formSubmitContext.Fields.FirstOrDefault(f => f.Name.Equals("txtName")));
            var emailFieldValue = GetValue(this._formSubmitContext.Fields.FirstOrDefault(f => f.Name.Equals("txtMail")));

            using (MailMessage mail = new MailMessage())
            {
                //email functinality
                //smtp.Send(mail);  scenario1 -->if email send successfully, i have to show custom message like "Message is send successfully"
            }
            return true;
        }
        catch (Exception e)
        {
            Log.Error($" mail failed ", e, this);
            formSubmitContext.Abort(); //scenario-2-- >if email failed, i have to show custom message like "Message is not send successfully"
        }
        return false;
    }
    protected override bool TryParse(string value, out string target)
    {
        target = string.Empty;
        return true;
    }
    private static string GetValue(object field)
    {
        return field?.GetType().GetProperty("Value")?.GetValue(field, null)?.ToString() ?? string.Empty;
    }
}