SmtpMail.Send - Exception: "Could not access 'CDO.Message' object"

[Jens]

Hi
I am writing a ASP.NET web application that must sent some e-mails.

I get the exception “Could not access 'CDO.Message' object� when I call SmtpMail.Send. This only happens when I send e-mail addresses out side my company walls. When the e-mail is send on some one in my company it works perfect.

I think it is a relay issue. Our system administrator will not allow relaying.

In the ASP.Net web.config file I let the web application impersonate a specific user that has a mail account on our mail server:

<identity impersonate="true" userName="MyDon\MyUserName" password="zzzz" />

The web server and the mail server are two different physical computers.

I have two questions:
1) How can I fix the problem?
2) Is it a relay issue? If yes, what can I do to fix it? Is it OK to allow relaying on a mail server?

Below you can se my code and the exceptions

Regards
Jens

Here you can see my code

Try

Mail.From = tbFrom.Text
Mail.To = tbTo.Text
Mail.Subject = tbSubject.Text
Mail.Body = tbMessage.Text

Dim SmtpMail As Mail.SmtpMail
SmtpMail.SmtpServer = "MyMailServerName"
SmtpMail.Send(Mail)

Catch ex As Exception

While (Not ex.InnerException Is Nothing)
Response.Write( _
"<b>Message:</b> " & ex.Message & "<br>" & _
"<b>Source:</b> " & ex.Source & "<br>" & _
"<b>StackTrace:</b> " & ex.StackTrace & "<br>" & _
"<b>HelpLink:</b> " & ex.HelpLink & "<br>" & _
"<b>UserName:</b> " & User.Identity.Name & "<br><br>")
ex = ex.InnerException
End While
End Try

Message: Could not access 'CDO.Message' object.
Source: System.Web
StackTrace: at System.Web.Mail.LateBoundAccessHelper.CallMethod(O bject obj, String methodName, Object[] args) at System.Web.Mail.CdoSysHelper.Send(MailMessage message) at System.Web.Mail.SmtpMail.Send(MailMessage message) at NCR2.SendMail.btSend_Click(Object sender, EventArgs e) in C:\Inetpub\wwwroot\NCR2\SendMail.aspx.vb:line 79

Message: Exception has been thrown by the target of an invocation.
Source: mscorlib
StackTrace: at System.RuntimeType.InvokeDispMethod(String name, BindingFlags invokeAttr, Object target, Object[] args, Boolean[] byrefModifiers, Int32 culture, String[] namedParameters) at System.RuntimeType.InvokeMember(String name, BindingFlags invokeAttr, Binder binder, Object target, Object[] args, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParameters) at System.Web.Mail.LateBoundAccessHelper.CallMethod(O bject obj, String methodName, Object[] args)

[bb]

Jens wrote:

Hi
I am writing a ASP.NET web application that must sent some e-mails.

I get the exception “Could not access 'CDO.Message' object� when I call SmtpMail.Send. This only happens when I send e-mail addresses out side my company walls. When the e-mail is send on some one in my company it works perfect.

I think it is a relay issue. Our system administrator will not allow relaying.

In the ASP.Net web.config file I let the web application impersonate a specific user that has a mail account on our mail server:

<identity impersonate="true" userName="MyDon\MyUserName" password="zzzz" />

The web server and the mail server are two different physical computers.

I have two questions:
1) How can I fix the problem?
2) Is it a relay issue? If yes, what can I do to fix it? Is it OK to allow relaying on a mail server?

Below you can se my code and the exceptions

Regards
Jens

Here you can see my code

Try

Mail.From = tbFrom.Text
Mail.To = tbTo.Text
Mail.Subject = tbSubject.Text
Mail.Body = tbMessage.Text

Dim SmtpMail As Mail.SmtpMail
SmtpMail.SmtpServer = "MyMailServerName"
SmtpMail.Send(Mail)

Catch ex As Exception

While (Not ex.InnerException Is Nothing)
Response.Write( _
"<b>Message:</b> " & ex.Message & "<br>" & _
"<b>Source:</b> " & ex.Source & "<br>" & _
"<b>StackTrace:</b> " & ex.StackTrace & "<br>" & _
"<b>HelpLink:</b> " & ex.HelpLink & "<br>" & _
"<b>UserName:</b> " & User.Identity.Name & "<br><br>")
ex = ex.InnerException
End While
End Try

Message: Could not access 'CDO.Message' object.
Source: System.Web
StackTrace: at System.Web.Mail.LateBoundAccessHelper.CallMethod(O bject obj, String methodName, Object[] args) at System.Web.Mail.CdoSysHelper.Send(MailMessage message) at System.Web.Mail.SmtpMail.Send(MailMessage message) at NCR2.SendMail.btSend_Click(Object sender, EventArgs e) in C:\Inetpub\wwwroot\NCR2\SendMail.aspx.vb:line 79

Message: Exception has been thrown by the target of an invocation.
Source: mscorlib
StackTrace: at System.RuntimeType.InvokeDispMethod(String name, BindingFlags invokeAttr, Object target, Object[] args, Boolean[] byrefModifiers, Int32 culture, String[] namedParameters) at System.RuntimeType.InvokeMember(String name, BindingFlags invokeAttr, Binder binder, Object target, Object[] args, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParameters) at System.Web.Mail.LateBoundAccessHelper.CallMethod(O bject obj, String methodName, Object[] args)

I used to get that message and wonder why the hell emails failed..

do this, to get the real error message of why the mail wasnt sent like
this ...

catch(Exception e)
{
e = e.GetBaseException();
log.Error("Error sending email via Server - + e.Message);
}

I now use both OpenSmtp and System.Web.Mail support in our applications
so that it can be configured on site. We find that the OpenSmtp library
provides much clearer diagnostics than CDONTS

Of course, this wont solve your problem, but may get you a meaningfull
error message ;-)

bb
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[Nick Gilbert]

I have found that this problem is sometimes caused by SMTP Server not
being set properly.

Try adding this line immediately before the .Send() line in your code:

SmtpMail.Server = "localhost";

(or preferably something not hardcoded:
SmtpMail.Server = ConfigurationSettings.AppSettings["SmtpServer"];
)

2) Is it a relay issue? If yes, what can I do to fix it?
Is it OK to allow relaying on a mail server?

No... If you're sending from a company e-mail address, then your server
should should regard the messages as coming from a local account and it
will deliver it. If you have to send messages from a different address,
then ensure that you limit relaying to the IP range of your internal
network. Do not under any circumstances allow external clients to relay
via your server - you will be RBL blacklisted and will find it very
difficult to send e-mail to anyone after that.

Nick...

[Jens]

Thank you, your answer leads me in the right direction. The solution to my
relay problem was:

I change the security settings of the mail server. The mail server now
allows relaying when the server that tries to relay is my web server
computer. And now it works :-)

In Exchange this is done as follows:

1) Select: Adm Groups | <Your mail group > | Servers | <Your Exchange
server> | Protocols | SMTP | <Your Web server>
2) Select the tab Access
3) Press Relay
4) Add the IP address to the web server
Regards,
Jens
"Nick Gilbert" wrote:

I have found that this problem is sometimes caused by SMTP Server not
being set properly.

Try adding this line immediately before the .Send() line in your code:

SmtpMail.Server = "localhost";

(or preferably something not hardcoded:
SmtpMail.Server = ConfigurationSettings.AppSettings["SmtpServer"];
)

> 2) Is it a relay issue? If yes, what can I do to fix it?
> Is it OK to allow relaying on a mail server?

No... If you're sending from a company e-mail address, then your server
should should regard the messages as coming from a local account and it
will deliver it. If you have to send messages from a different address,
then ensure that you limit relaying to the IP range of your internal
network. Do not under any circumstances allow external clients to relay
via your server - you will be RBL blacklisted and will find it very
difficult to send e-mail to anyone after that.

Nick...