new MailAddress() Exits out of method

Question

I have a fairly weird issue that I can't wrap my head around. So here is the code:

[HttpGet]
[AllowAnonymous]
public ActionResult SendEmail()
{
    SendRegisterEmail("Test", "Testagain", "lastTest");
    return View("Index");
}

public async Task<bool> SendRegisterEmail(string subject, string message, string to)
{
    var email = new Email();
    var mailAddress = new MailAddress(to);
    email.Subject = subject;
    email.Body = message;
    var mailAddressCollection = new MailAddressCollection();
    mailAddressCollection.Add(mailAddress);
    email.To = (mailAddressCollection);

    return await Send(email);
}

Now to prove my problem I broke down the code into single lines so I can see on which line it breaks. Here is what I found:

When I debug this and I step into the SendRegisterEmail method, the line that says var mailAddress = new MailAddress(to); gets run and then it exits out the function and runs the line return View("Index"); and the page loads up. The weird thing is I added a logging method on to Send at the very end and that logging never gets hit. I put a breakpoint on Send and it never got hit. It is as if creation of email crashed, decided to exit out to the caller function and continued with the code.

I don't have a faintest clue as to why.

Answer 1

SendRegisterEmail method is asynchronous, you're not awaiting for it.

Currently, you start a fire-and-forget operation and return View instruction is executed while you're creating a new MailAddress instance. Most probably it throws FormatException which you can't catch because the exception is thrown in another thread.

update your action method to

public async Task <ActionResult> SendEmail()
{
    await SendRegisterEmail("Test", "Testagain", "lastTest");
    return View("Index");
}

Also awaiting before the return is not really needed, you can change it to

public Task<bool> SendRegisterEmail(string subject, string message, string to)
{
    var email = new Email();
    // ... 
    return Send(email);
}

but that's not related to the problem you've got.