Some functions using Send Grid to send emails

SendGrid.cs

    /// <summary>
    /// Functions for sending emails using SendGrid
    /// </summary>
    public class SendGrid
    {
        #region Dependency and Initialization
        private static SendingEmailSetting setting;

        /// <summary>
        /// This need to be set up when application starts
        /// </summary>
        /// <param name="set">The setting</param>
        public static void InitializeSetting(SendingEmailSetting set)
        {
            setting = set;
        } 
        #endregion

        #region Send Email Using SendGrid
        /// <summary>
        /// Send Email out use SendGrid
        /// </summary>
        /// <param name="ID"></param>
        /// <param name="toAddress"></param>
        /// <param name="subject"></param>
        /// <param name="body"></param>
        /// <param name="deliveryAttempts"></param>
        /// <param name="replyToAddress"></param>
        /// <returns></returns>
        public static bool SendEmail(Guid ID, string toAddress, string subject, string body, List<string> categories, ref int deliveryAttempts, string replyToAddress = "help@company.com")
        {
            string sendGridAPIKey = setting.SendGridAPIKey;
            string sendGridPassword = setting.SendGridAPIPassword;
            string fromEmail = setting.FromEmail;
            int maximumDeliveryAttempts = setting.EmailDeliveryMaxAttemps;

            if (deliveryAttempts >= maximumDeliveryAttempts || IsEmailInBounceList(toAddress) || IsEmailInInvalidEmailList(toAddress)
                || IsEmailInSpamReport(toAddress) || IsEmailInUnsubscribeList(toAddress) || toAddress.EndsWith("-removed"))
            {
                deliveryAttempts = -1;
                TraceInformation(string.Format("Email sending attempts reached limit or it is on the no sending list. ID: {0}. EmailAddress: {1}", ID.ToString(), toAddress));
                return false;
            }
            else
            {
                try
                {
                    return SendEmailBase(toAddress, subject, body, replyToAddress, sendGridAPIKey, sendGridPassword, fromEmail, categories);
                }
                catch (Exception ex)
                {
                    TraceError(string.Format("SendGrid.SendEmail Exception. ID: {0}. ToEmail: {1}. ex: {2}", ID.ToString(), toAddress, ex.Message), ex);
                    return false;
                }
            }
        }

        /// <summary>
        /// Simplified function for sending email directly.
        /// </summary>
        /// <param name="toAddress"></param>
        /// <param name="subject"></param>
        /// <param name="body"></param>
        /// <param name="replyToAddress"></param>
        /// <returns></returns>
        public static bool SendEmailSimple(string toAddress, string subject, string body, List<string> categories, string replyToAddress = "")
        {
            string sendGridAPIKey = setting.SendGridAPIKey;
            string sendGridPassword = setting.SendGridAPIPassword;
            string fromEmail = setting.FromEmail;

            try
            {
                return SendEmailBase(toAddress, subject, body, replyToAddress, sendGridAPIKey, sendGridPassword, fromEmail, categories);
            }
            catch (Exception ex)
            {
                TraceError(string.Format("SendGrid.SendEmail Exception. Subject: {0}. ToAddress: {1}.", subject, toAddress), ex);
                return false;
            }

        }

        public static bool SendEmailBase(string toAddress, string subject, string body, string replyToAddress, string sendGridAPIKey, string sendGridPassword, string fromEmail, List<string> categories)
        {
            string header = "";

            if (categories != null && categories.Count == 1)
            {
                header = "{\"category\":\"" + categories[0] + "\"}";
            }
            else
            {
                StringBuilder sb = new StringBuilder("{\"category\":[\"");
                if (categories != null && categories.Count > 0)
                {
                    for (int i = 0; i < categories.Count; i++)
                    {
                        sb.Append(categories[i]);
                        if (i != categories.Count - 1)
                        {
                            sb.Append("\",\"");
                        }
                    }
                    sb.Append("\"]}");
                    header = sb.ToString();
                }
            }

            MailMessage mailMsg = new MailMessage();
            //Categories for SendGrid
            if (!string.IsNullOrWhiteSpace(header))
            {
                mailMsg.Headers.Add("X-SMTPAPI", header);
            }
            // To
            mailMsg.To.Add(new MailAddress(toAddress));
            // From
            mailMsg.From = new MailAddress(fromEmail, "CompanyName");

            if (replyToAddress != "")
            {
                mailMsg.ReplyToList.Add(new MailAddress(replyToAddress));
            }
            // Subject and multipart/alternative Body
            mailMsg.Subject = subject;
            string html = body;
            mailMsg.AlternateViews.Add(AlternateView.CreateAlternateViewFromString(html, null, MediaTypeNames.Text.Html));
            //mailMsg.AlternateViews.Add(AlternateView.CreateAlternateViewFromString(text, null, MediaTypeNames.Text.Plain));
            // Init SmtpClient and send
            SmtpClient smtpClient = new SmtpClient("smtp.sendgrid.net", Convert.ToInt32(587));
            System.Net.NetworkCredential credentials = new System.Net.NetworkCredential(sendGridAPIKey, sendGridPassword);
            smtpClient.Credentials = credentials;
            smtpClient.Send(mailMsg);
            return true;
        }

        /// <summary>
        /// Send Email out use SendGrid
        /// </summary>
        /// <param name="ID"></param>
        /// <param name="toAddress"></param>
        /// <param name="subject"></param>
        /// <param name="body"></param>
        /// <param name="deliveryAttempts"></param>
        /// <param name="replyToAddress"></param>
        /// <returns></returns>
        public static bool SendEmailForNewsLetter(Guid ID, string toAddress, string subject, string body, List<string> categories, ref int deliveryAttempts, string replyToAddress = "")
        {
            string sendGridAPIKey = setting.SendGridAPIKey;
            string sendGridPassword = setting.SendGridAPIPassword;
            string fromEmail = setting.FromEmail;
            int maximumDeliveryAttempts = setting.EmailDeliveryMaxAttemps;

            if (deliveryAttempts >= maximumDeliveryAttempts || IsEmailInBounceList(toAddress) || IsEmailInInvalidEmailList(toAddress)
                || IsEmailInSpamReport(toAddress) || IsEmailInUnsubscribeList(toAddress) || toAddress.EndsWith("-removed"))
            {
                deliveryAttempts = -1;
                TraceInformation(string.Format("Email sending attempts reached limit or it is on the no sending list. ID: {0}. EmailAddress: {1}", ID.ToString(), toAddress));
                return false;
            }
            else
            {
                try
                {
                    return SendEmailBase(toAddress, subject, body, replyToAddress, sendGridAPIKey, sendGridPassword, fromEmail, categories);
                }
                catch (Exception ex)
                {
                    TraceError("SendGrid.SendEmail Exception. ID: " + ID.ToString() + ";" + ex.Message, ex);
                    return false;
                }
            }
        }
        #endregion

        /// <summary>
        /// Add Email address to unsubscribe list
        /// </summary>
        /// <param name="emailAddress">email address to delete</param>
        /// <returns><c>true</c> if email is successfully added to the list, otherwise <c>false</c></returns>
        public static bool AddEmailToUnsubscribeList(string emailAddress)
        {
            emailAddress = emailAddress.ToLower();
            if (IsEmailInUnsubscribeList(emailAddress))
            {
                //Email already exist in the unsubscribe list
                return true;
            }
            try
            {
                string sendGridAPIKey = setting.SendGridAPIKey;
                string sendGridPassword = setting.SendGridAPIPassword;
                string requestUri = string.Format("https://sendgrid.com/api/unsubscribes.add.json?api_user={0}&amp;api_key={1}&amp;email={2}", sendGridAPIKey, sendGridPassword, emailAddress);

                // Create the web request
                HttpWebRequest request = WebRequest.Create(requestUri) as HttpWebRequest;
                request.Method = "POST";
                request.ContentType = "application/x-www-form-urlencoded";
                // Get response  
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    // Get the response stream  
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    //Return – Success: [{"message":"success"}]
                    //Return – Error: {"message":"error","errors":[..."error messages"...]}                  
                    string resultStr = reader.ReadToEnd().Trim();
                    resultStr = resultStr.Replace("[", "").Replace("]", "");
                    JObject result = JObject.Parse(resultStr);
                    string message = (string)result["message"];
                    if (message.ToLower() == "success")
                    {
                        return true;
                    }
                    else
                    {
                        TraceWarning(string.Format("SendGrid.AddEmailToUnsubscribeList. Email: {0}.", emailAddress), result);
                        return false;
                    }
                }
            }
            catch (Exception ex)
            {
                TraceError("SendGrid.AddEmailToUnsubscribeList Error", ex);
                return false;
            }
        }

        /// <summary>
        /// Delete the email address from unsubscribe List
        /// </summary>
        /// <param name="emailAddress">email address to delete</param>
        /// <returns><c>true</c> if email is successfully delete, otherwise <c>false</c></returns>
        public static bool DeleteEmailFromUnsubscribeList(string emailAddress)
        {
            if (!IsEmailInUnsubscribeList(emailAddress))
            {
                //Email not exist in the unsubscribe list
                return true;
            }
            try
            {
                string sendGridAPIKey = setting.SendGridAPIKey;
                string sendGridPassword = setting.SendGridAPIPassword;
                string requestUri = string.Format("https://sendgrid.com/api/unsubscribes.delete.json?api_user={0}&amp;api_key={1}&amp;email={2}", sendGridAPIKey, sendGridPassword, emailAddress);

                // Create the web request
                HttpWebRequest request = WebRequest.Create(requestUri) as HttpWebRequest;
                request.Method = "POST";
                request.ContentType = "application/x-www-form-urlencoded";
                // Get response  
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    // Get the response stream  
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    //Return – Success: [{"message":"success"}]
                    //Return – Error: [{"message":"error","errors":[..."error messages"...]}]
                    string resultStr = reader.ReadToEnd().Trim();
                    resultStr = resultStr.Replace("[", "").Replace("]", "");
                    JObject result = JObject.Parse(resultStr);
                    string message = (string)result["message"];
                    if (message.ToLower() == "success")
                    {
                        return true;
                    }
                    else if (message.ToLower() == "email does not exist")
                    {
                        return true;
                    }
                    else
                    {
                        TraceWarning(string.Format("SendGrid.DeleteEmailFromUnsubscribeList Error: {0}. Email: {1}.", result, emailAddress));
                        return false;
                    }

                }
            }
            catch (Exception ex)
            {
                TraceError("SendGrid.AddEmailToUnsubscribeList Error", ex);
                return false;
            }
        }

        /// <summary>
        /// Check if an email address is in the unsubscribe list of SendGrid
        /// </summary>
        /// <param name="emailAddress">email address to check</param>
        /// <returns><c>true</c> if email is in the list, otherwise <c>false</c></returns>
        public static bool IsEmailInUnsubscribeList(string emailAddress)
        {
            try
            {
                string sendGridAPIKey = setting.SendGridAPIKey;
                string sendGridPassword = setting.SendGridAPIPassword;
                string requestUri = string.Format("https://sendgrid.com/api/unsubscribes.get.json?api_user={0}&amp;api_key={1}&amp;email={2}", sendGridAPIKey, sendGridPassword, emailAddress);

                // Create the web request
                HttpWebRequest request = WebRequest.Create(requestUri) as HttpWebRequest;
                // Get response  
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    // Get the response stream  
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    //If Email is in the unsubscribe list, then return the email address itself, 
                    //otherwise return empty string if there is no error.
                    //If there is an error, return the error message
                    string resultStr = reader.ReadToEnd().Trim();
                    resultStr = resultStr.Replace("[", "").Replace("]", "");
                    if (string.IsNullOrWhiteSpace(resultStr))
                    {
                        return false;
                    }
                    JObject result = JObject.Parse(resultStr);
                    string message = (string)result["email"];

                    if (message == emailAddress)
                    {
                        return true;
                    }
                    else
                    {
                        TraceWarning("SendGrid.IsEmailInUnsubscribeList Error: " + result);
                        return false;
                    }
                }
            }
            catch (Exception ex)
            {
                TraceError("SendGrid.IsEmailInUnsubscribeList Error", ex);
                return false;
            }
        }

        /// <summary>
        /// Check if an email address is in the bounce list of SendGrid
        /// </summary>
        /// <param name="emailAddress">email address to check</param>
        /// <returns><c>true</c> if email is in the list, otherwise <c>false</c></returns>
        public static bool IsEmailInBounceList(string emailAddress)
        {
            try
            {
                string sendGridAPIKey = setting.SendGridAPIKey;
                string sendGridPassword = setting.SendGridAPIPassword;
                string requestUri = string.Format("https://sendgrid.com/api/bounces.get.json?api_user={0}&amp;api_key={1}&amp;email={2}", sendGridAPIKey, sendGridPassword, emailAddress);

                // Create the web request
                HttpWebRequest request = WebRequest.Create(requestUri) as HttpWebRequest;
                // Get response  
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    // Get the response stream  
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    //If Email is in the unsubscribe list, then return the email address itself, 
                    //otherwise return empty string if there is no error.
                    //If there is an error, return the error message
                    string resultStr = reader.ReadToEnd().Trim();
                    resultStr = resultStr.Replace("[", "").Replace("]", "");
                    if (string.IsNullOrWhiteSpace(resultStr))
                    {
                        return false;
                    }
                    JObject result = JObject.Parse(resultStr);
                    string message = (string)result["email"];

                    if (message == emailAddress)
                    {
                        return true;
                    }
                    else
                    {
                        TraceWarning("SendGrid.IsEmailInBounceList Error: " + result);
                        return false;
                    }
                }
            }
            catch (Exception ex)
            {
                TraceError("SendGrid.IsEmailInBounceList Error", ex);
                return false;
            }
        }

        /// <summary>
        /// Check if an email address is in the invalid Email list of SendGrid
        /// </summary>
        /// <param name="emailAddress">Email Address to check</param>
        /// <returns><c>true</c> if email is in the list, otherwise <c>false</c></returns>
        public static bool IsEmailInInvalidEmailList(string emailAddress)
        {
            try
            {
                string sendGridAPIKey = setting.SendGridAPIKey;
                string sendGridPassword = setting.SendGridAPIPassword;
                string requestUri = string.Format("https://sendgrid.com/api/invalidemails.get.json?api_user={0}&amp;api_key={1}&amp;email={2}", sendGridAPIKey, sendGridPassword, emailAddress);

                // Create the web request
                HttpWebRequest request = WebRequest.Create(requestUri) as HttpWebRequest;
                // Get response  
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    // Get the response stream  
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    //If Email is in the unsubscribe list, then return the email address itself, 
                    //otherwise return empty string if there is no error.
                    //If there is an error, return the error message
                    string resultStr = reader.ReadToEnd().Trim();
                    resultStr = resultStr.Replace("[", "").Replace("]", "");
                    if (string.IsNullOrWhiteSpace(resultStr))
                    {
                        return false;
                    }
                    JObject result = JObject.Parse(resultStr);
                    string message = (string)result["email"];

                    if (message == emailAddress)
                    {
                        return true;
                    }
                    else
                    {
                        TraceWarning("SendGrid.IsEmailInInvalidEmailList Error: " + result);
                        return false;
                    }
                }
            }
            catch (Exception ex)
            {
                TraceError("SendGrid.IsEmailInInvalidEmailList Error", ex);
                return false;
            }
        }

        /// <summary>
        /// Check if an email address is in the spam report email list of SendGrid
        /// </summary>
        /// <param name="emailAddress">Email Address to check</param>
        /// <returns><c>true</c> if email is in the spam report list, otherwise <c>false</c></returns>
        public static bool IsEmailInSpamReport(string emailAddress)
        {
            try
            {
                string sendGridAPIKey = setting.SendGridAPIKey;
                string sendGridPassword = setting.SendGridAPIPassword;
                string requestUri = string.Format("https://sendgrid.com/api/spamreports.get.json?api_user={0}&amp;api_key={1}&amp;email={2}", sendGridAPIKey, sendGridPassword, emailAddress);

                // Create the web request
                HttpWebRequest request = WebRequest.Create(requestUri) as HttpWebRequest;
                // Get response  
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    // Get the response stream  
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    //If Email is in the unsubscribe list, then return the email address itself, 
                    //otherwise return empty string if there is no error.
                    //If there is an error, return the error message
                    string resultStr = reader.ReadToEnd().Trim();
                    resultStr = resultStr.Replace("[", "").Replace("]", "");
                    if (string.IsNullOrWhiteSpace(resultStr))
                    {
                        return false;
                    }
                    JObject result = JObject.Parse(resultStr);
                    string message = (string)result["email"];

                    if (message == emailAddress)
                    {
                        return true;
                    }
                    else
                    {
                        TraceWarning("SendGrid.IsEmailInSpamReport Error: " + result);
                        return false;
                    }
                }
            }
            catch (Exception ex)
            {
                TraceError("SendGrid.IsEmailInSpamReport Error", ex);
                return false;
            }
        }
    }