CODEWITHSUNDEEP
c#asp.net-mvcmvcmailer
astian
astian

Reputation: 684

Sending multiple emails with transaction behavior (if one fails no emails get send)

Sorry if I failed to find an existing post with my problem.

What am I trying to do is as follows:

I simply want to send a couple of emails (2-3) to different people and more importantly with different content. The emails are official, important and also logged in the system. Long story short, I need when for some reason one of them fails to stop the sending of the others. I need either all of them sent or none of them.

What have I done so far

It is not the first time the system I worked on has to send an automatic email. The application is an ASP MVC website. So some time ago, I installed the MvcMailer (MvcMailer) and used it the way it was explained. It worked quite well and so I liked the idea of previewing the email (as you can give it a view to send).

So, in the light of my new problem I read carefully the MvcMailer documentation and did not find anything about sending multiple emails in transaction-like manner. Couldn't think of a way to force them to behave in this way. In my tests when I send an email, even if it is one email with a few CCs, all working mails get send and just one of them fails (wrong email name, closed port ... whatever).

I was hoping someone could suggest me a way to achieve something like this. I hope my explanation was sufficient and if not, let me know I will provide you with all details required.

If this is impossible with the MvcMailer, then is it possible with other tools ?

My implementation so far: (keep in mind I'm still in the testing stages)

public class MailerController : Controller
{
   private MailerRepository mailerRep;

   public MailerController()
   {
       this.mailerRep = new MailerRepository();
   }

   public void TestTransmittalEmail()
   {
       var model = this.mailerRep.GetTransmittalModel(1234); //I've stucked a specific clientId
       var mailer = new TransmittalsMailer();
       mailer.TransmittalEmail(model).Send();
   }
}

public class TransmittalsMailer : MailerBase
{
    public TransmittalsMailer()
    {

    }

    public MvcMailMessage TransmittalEmail(TransmittalManifestModel model)
    {
        var mailMessage = new MvcMailMessage() { Subject = "Transmittals - TESTING EMAIL" };
        //embedding a few images in the email
        var resources = new Dictionary<string, string>();
        resources["logo"] = PDFResourcePaths.VripackLogo;
        resources["companyInfo"] = PDFResourcePaths.CompanyInfoBlock;

        mailMessage.To.Add("[email protected]");

        mailMessage.Attachments.Add(new Attachment(@"D:\ASD\TransmittalFolders\1\Archives\150812.1433.MMA.rar"));

        ViewData["model"] = model;
        this.PopulateBody(mailMessage, "TransmittalEmailView", resources);

        return mailMessage;
    }
}

Upvotes: 2

Views: 1414

Answers (2)

user1666620
user1666620

Reputation: 4808

You can check if an exception is thrown and then cancel the sending of subsequent emails until the issue is addressed. However this only deals with issues on your end on the sending of each email individual email. If the first two mails are successfully sent, and the last throws an exception, you can't unsend the first emails.

A possible workaround (ugly as it is) would be to initially send emails to an email address you control. If an exception is thrown at this step, log the error, and do not send any further emails until the error is dealt with. If no exceptions are raised, send the emails. However this does not and cannot handle issues that may occur on the recipients side.

A delivery failure notice is not guaranteed as depending on the configuration of your SMTP and the recipient SMTP a delivery failure notification might not be sent. Even if delivery failure notifications are enabled, the notification might not be sent for days (in one of my previous jobs, email delivery failure notifications were not sent until 14 days had elapsed).

Ideally, this should be dealt with at the initial input of the email addresses before you ever send any documents to anyone. You simply send a verification email to the email address in question and have the user clicking on a verification link back to a web service you control. Until this has been done, you don't send any emails to the intended recipient.

Upvotes: 1

Mr. B
Mr. B

Reputation: 2965

This is actually quite a difficult problem to solve. This is because when you send an email, it will work as long the SMTP server can be found (no exception will be thrown).

So you basically have to wait some arbitrary amount of time, and check the inbox of the email you sent it from for the delivery failure. If there is a delivery failure, you stop sending.

So long story short, you shouldn't probably do this. You should simply send all three and notify yourself some other way (probably another email) that there was a failure and which email failed.

Upvotes: 4

Related Questions