What is the best way to implement Email functionaity across the application?

ASP.NET MVC has provided you with Controllers, try adding a controller to your application that manages the Emails. Such as,

public class EmailController : Controller 
{
   // Create private and public members for to and from etc. 
   public ActionResult Send(object parameter)
   {
       // Change object to any type, a model or form etc.
   }
   // ... Rest of stuff
}

Now, this can be use from any page. Just submit the form to your /email/ location and controller will be able to send the email to client.

Good thing is that you would be provided with separate Views for this controller and you may want to use a Model (which would hold, details for the email. Such as To, From, Subject, Body etc.) Then you can pass that model to Send action and action may send the email by using the member fields in the Model object. This way, you will be able to set up some parameters the one you are talking about, Email language, GotoUrl etc.

Anyways, you must also consider keeping the passwords safe somewhere, do not expose them to the public.

if you want it to be pretty, functional and available everywhere, this is what I would do:

1. Create a main private base function for sending email.
2. Create a private function for each type of email that will invoke the base function with the right parameters.
3. Create an Enum with email types.
4. Create a public static function that will take the parameters along with Enum parameter (from number 3) which will according to the Enum invoke the right private function, and put that function in a static class that will be outside of any namespace... something like NativeMethods etc...

*Also I would create the base email function to work in a Task, so if I takes long time it won't freeze the main thread.

Try below code to send mail using gmail.

public string senMail(string emailId, string MailBody)
        {
            try
            {
                MailMessage mail = new MailMessage();
                SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com"); //Gmail SMTP Client

                mail.From = new MailAddress("abc@gmail.com"); //Sender email ID 
                mail.To.Add(emailId);
                mail.Subject = "Email Subject";
                mail.Body = mailBody;

                SmtpServer.Port = 587;
                SmtpServer.Credentials = new System.Net.NetworkCredential("abc@gmail.com", "abc152wte.7"); //Sender email and password (login credential)
                SmtpServer.EnableSsl = true;
                SmtpServer.Send(mail);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            return "";
        }

Hi,

below is the generic code to implement Email functionality :

public static bool SendMail(string mailTo, string mailFrom, string mailcc, string mailSubject, string filepath, bool isHtml, ListDictionary replacements, string mailBody, List<memorystream> attachmentFiles = null, List<string> fileNamesList = null, List<string> fileContentType = null)
        {

            bool isSend;

            try
            {
                // string mailBody;
                if (!string.IsNullOrEmpty(filepath))
                {
                    using (StreamReader sr = new StreamReader(filepath))
                    {
                        mailBody = sr.ReadToEnd();
                    }
                }

                if (!string.IsNullOrEmpty(mailBody))
                {

                    string mailServer = Convert.ToString(ConfigurationManager.AppSettings["SMTPServer"]);
                    string username = Convert.ToString(ConfigurationManager.AppSettings["SMTP_Username"]);
                    string password = Convert.ToString(ConfigurationManager.AppSettings["SMTP_Password"]);
                    int portAddress = Convert.ToInt32(ConfigurationManager.AppSettings["SMTP_Port"]);

                    bool useDefaultCredentials = Convert.ToBoolean(ConfigurationManager.AppSettings["SMTP_UseDefaultCredentials"]);

                    MailMessage mailmsg = new MailMessage();
                    MailAddress mailFromAdrs = new MailAddress(mailFrom);

                    mailmsg.From = mailFromAdrs;
                    mailmsg.To.Add(mailTo);

                    if (!string.IsNullOrEmpty(mailcc))
                        mailmsg.CC.Add(mailcc);

                    if (replacements != null)
                    {
                        IEnumerator iEnumReplacements = replacements.GetEnumerator();
                        bool hasValues = iEnumReplacements.MoveNext();
                        while (hasValues)
                        {
                            DictionaryEntry lstReplacements = (DictionaryEntry)iEnumReplacements.Current;
                            mailSubject = mailSubject.Replace(lstReplacements.Key.ToString(), lstReplacements.Value.ToString());
                            mailBody = mailBody.Replace(lstReplacements.Key.ToString(), lstReplacements.Value.ToString());

                            hasValues = iEnumReplacements.MoveNext();
                        }
                    }

                    mailmsg.Subject = mailSubject;
                    mailmsg.Body = mailBody;
                    mailmsg.IsBodyHtml = isHtml;

                    if (attachmentFiles != null && attachmentFiles.Count() > 0)
                    {
                        for (int i = 0; i < attachmentFiles.Count(); i++)
                        {                           
                            if (fileNamesList != null && fileContentType != null)
                                mailmsg.Attachments.Add(new Attachment(attachmentFiles[i], fileNamesList[i], fileContentType[i]));
                        }
                    }

                    NetworkCredential smtpUserInfo = new NetworkCredential(username, password);
                    SmtpClient smtpclient = new SmtpClient { Host = mailServer };
                    if (portAddress > 0)
                        smtpclient.Port = portAddress;
                    smtpclient.UseDefaultCredentials = false;


                    if (useDefaultCredentials)
                        smtpclient.UseDefaultCredentials = true;
                    else
                        smtpclient.Credentials = smtpUserInfo;

                    smtpclient.Send(mailmsg);

                    isSend = true;
                }
                else
                    isSend = false;
            }
            catch
            {
                isSend = false;
            }

            return isSend;
        }</string></string></memorystream>