Using Postal with QueueBackgroundWorkItem - The request lifetime scope cannot be created > because the HttpContext is not available

Question

I'm using Postal to send emails. My application is an ASP.net MVC application. I use Autofac (MVC5 integration)

I've set up Postal like so:

        dynamic email = new Email("TemplateName");
        email.To = "test@email.com";
        email.From = "sendertest@email.com";

        email.TemplateValue = "This is a value";

        var service = new EmailService();

        HostingEnvironment.QueueBackgroundWorkItem(ct =>
        {
            service.Send(email);
        });

This fails with the following error:

An exception of type 'System.InvalidOperationException' occurred in Autofac.Integration.Mvc.dll but was not handled in user code

Additional information: The request lifetime scope cannot be created because the HttpContext is not available.

   at Autofac.Integration.Mvc.RequestLifetimeScopeProvider.GetLifetimeScope(Action`1 configurationAction)  
   at Autofac.Integration.Mvc.AutofacDependencyResolver.get_RequestLifetimeScope()  
   at Autofac.Integration.Mvc.AutofacDependencyResolver.GetService(Type serviceType)  
   at System.Web.Mvc.BuildManagerViewEngine.DefaultViewPageActivator.Create(ControllerContext controllerContext, Type type)  
   at System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer)  
   at Postal.EmailViewRenderer.RenderView(IView view, ViewDataDictionary viewData, ControllerContext controllerContext, ImageEmbedder imageEmbedder)  
   at Postal.EmailViewRenderer.Render(Email email, String viewName)  
   at Postal.EmailService.CreateMailMessage(Email email)  
   at Postal.EmailService.Send(Email email)  
   at CallSite.Target(Closure , CallSite , EmailService , Object )  
   at System.Dynamic.UpdateDelegates.UpdateAndExecuteVoid2[T0,T1](CallSite site, T0 arg0, T1 arg1)  
   at EmailSender.<>c__DisplayClass3_0.<Handle>b__0(CancellationToken ct) in .....EmailSender.cs:line 42  
   at System.Web.Hosting.HostingEnvironment.<>c__DisplayClass91_0.<QueueBackgroundWorkItem>b__0(CancellationToken ct)  
   at System.Web.Hosting.BackgroundWorkScheduler.<RunWorkItemImpl>d__7.MoveNext()

If I take the service.Send(email); out of the QueueBackgroundWorkItem it works.

I understand this is because HttpContext.Current isn't available - but is there a way I can send emails using Postal on a background thread?

score 2 · Accepted Answer · answered Mar 17 '16 at 13:59

2

Postal is able to just create a MailMessage object, without sending it. See http://aboutcode.net/postal/create-mail-message.html

So you could do this within the MVC controller action, while the HttpContext is still alive.

Then, send the MailMessage in your background thread, using your own instance of SmtpClient.

answered Mar 17 '16 at 13:59

Andrew Davey

5,441
3
43
57

Hi I am facing this same problem can you give me more guidance on how to implement this solution. How to send the email after it has been created using own instance of smtpClient – Diin Jun 17 '16 at 16:48

score 0 · Answer 2 · answered Mar 17 '16 at 13:57

Have you tried creating a custom view engine?

As suggested here, is possibile to use postal outside of ASP.NET request scope (I know you're using MVC 5, but looks like the same situation to me).

If you still getting error, probably is a problem of Autofac registration: did you register something in the request scope, like this .InstancePerRequest(); ? In that case Autofac will no be able to resolve that components outside of the pipeline.

Using Postal with QueueBackgroundWorkItem - The request lifetime scope cannot be created > because the HttpContext is not available

2 Answers2