Getting System.Net.Mail to read from app.settings?

Question

In ASP.NET, I can just put my mailSettings in web.config and then System.Net.Mail.SmtpClient's default constructor will read them. In a regular VB.NET project, not ASP.NET, I thought I could just put mailSettings in app.config. However, SmtpClient() doesn't appear to read settings from app.config. Is there a step I'm missing in order to tell a VB.NET application to read from app.config?

Answer 1

the Asp.Net runtime has extra code to handle this for you, probably because the designers expect sending emails to be a normal part of a web site's operations (but I probably shouldn't guess about Microsoft's motives.)

You can read the setting yourself and set the smtp host by reading the settings with the System.Configuration.ConfigurationManager.

Or, since you're in VB, you can access this more easily by using My.Settings

Answer 2

This appears to work for me:

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <system.net>
    <mailSettings>
      <smtp>
        <network host="mysmtphost" />
      </smtp>
    </mailSettings>
  </system.net>
</configuration>

Module1.vb

Imports System.Net.Mail

Module Module1

    Sub Main()
        Dim client As New SmtpClient()
        Console.WriteLine(client.Host)
        ' output is "mysmtphost" as expected
    End Sub

End Module

Answer 3

The SmtpClient will not read it automagically, but you can do it easily...

for eg, in V2.0 of the framework, you could do this:

String host = (String)ConfigurationSettings.AppSettings["SmtpHostName"]

and in your app.exe.config file:

<configuration>
<appSettings>
<add key="SmtpHostName" value="Smtp.mydomain.com"/>
</appSettings>
</configuration>

Hope this helps.