.NET Why can't I override my web.config mailSettings?

Question

Usually my application sends email with a generic system address. But in some cases I want to instead send as the logged in user.

web.config:

<?xml version="1.0"?>
<configuration>
    ...
    <appSettings>
        ...
        <add key="DefaultEmailAddress"
             value="[email protected]" />
    </appSettings>
    <system.net>
        <mailSettings>
            <smtp>
                <network host="servername"
                         port="25"
                         userName="noreply"
                         password="apple" />
            </smtp>
        </mailSettings>
    </system.net>
    ...
</configuration>

This code fails to override that default sender from web.config:

Dim from As String = ConfigurationManager.AppSettings("DefaultEmailAddress")
Dim to As String = "[email protected]"
Dim m As New Mail.MailMessage(from, to)
m.IsBodyHtml = True
m.Subject = "Test"
m.Body = "<p>This is a test.</p>"

Dim c As New System.Net.Mail.SmtpClient

If CurrentUser.HasExchangeCredentials Then
    Dim userName As String = CurrentUser.ExchangeUserName
    Dim password As String = CurrentUser.ExchangePassword
    Dim address As String = CurrentUser.EmailAddress
    c.UseDefaultCredentials = False
    c.Credentials = New System.Net.NetworkCredential(userName, password)
    m.Sender = New Mail.MailAddress(address)
End If

c.Send(m)

My email goes out, but it is sent as [email protected] and also doesn't show up in my Outlook Sent folder.

I don't want to UseDefaultCredentials. I want to use a new, different NetworkCredential.

I'm using Microsoft Exchange.

Answer 1

In your code above, I don't see where you are overriding the default Sender. You are setting the "From" value to [email protected]:

Dim from As String = ConfigurationManager.AppSettings("DefaultEmailAddress")

You should try something like:

Dim from As String = CurrentUser.ExchangeUserName

This will use that user's email address instead of the value located in your web.config file.

Answer 2

I think this answers your question:

http://www.vbdotnetforums.com/vb-net-general-discussion/14895-system-net-mail-mailmessage-sender-vs-system-net-mail-mailmessage.html

Sender and From are separate. Changing the sender will not change the From address.

In your code set the From Property to your address variable.