RE: SmtpAppender not working

6 Apr 2005 19:24:30 -0000

I agreed with you until I just thought of something: MailMessage uses static properties to set the SMTP server etc. Tell me if I'm wrong, but that affects anything that's using MailMessage, on a per-process basis. So, if my system is using MailMessage to send email, and I set my message up and get it ready to send but then make a call to logging functionality before actually sending the mail, it might go through a different SMTP server than I intended, right?

I'm not sure if this is a big problem, but it could be a subtle one. And multi-threading issues could come into play too. That could get tough to debug.

Baron

--
"I am as bad as the worst, but, thank God, I am as good as the best."
    - Walt Whitman

On Sat, 2 Apr 2005, Nicko Cadell wrote:

Baron,

The runtime provides SMTP support through the MailMessage. Microsoft
have chosen to implement it using their CDO library. Usually CDO works
fine, however it is possible for it to be disabled.

While it should be simple to implement a system that sends mail directly
via port 25 I'm not sure it this is necessarily the best use of
resources as CDO works out of the box.

If someone wants to look at doing this it may be best to make the mail
sending functionality of the SmtpAppender pluggable between the current
MailMessage and an independent implementation.

Nicko

-----Original Message-----
From: Baron Schwartz [mailto:[EMAIL PROTECTED]
Sent: 24 March 2005 14:27
To: Log4NET User
Subject: RE: SmtpAppender not working

Thanks Nicko.

I have searched more on the various error messages and found
that indeed it is a problem with CDO on my laptop.  When I
configure the logging on the production machines, it works
fine.  I'm not familiar with what CDO is or how/why it's not
working on my laptop, other than maybe I borked it up when I
turned off every non-essential service (I believe the Systems
staff has all sorts of stuff running on the production
servers... not my job).

I did try using the fully qualified name of the SMTP machine,
and even its IP address; like I said I've had no problems
with sending to that machine with the SMTP software I've
written (telnet, too).

I looked through the source code for the SmtpAppender more.
I'm not sure how many people would use the more advanced
settings, such as sending through the credentials of the
process under which log4net runs -- and I know it's bad to
reinvent the wheel.  But, just to play devil's advocate, is
there any justification for an SMTP appender which sends via
plain SMTP, without relying on System.Web.Mail?  SMTP is
trivial to implement, and this might ease the problems, and
may even be more efficient as an appender.  I saw a lot of
griping on the Internet about this CDO issue, with no real
resolutions.  It sounds like there may be some Microsoftish
"extend the standard" issues with CDO.  But I'm no expert on
it, as I said.

Baron

On Thu, 24 Mar 2005, Nicko Cadell wrote:

  "The transport failed to connect to the server"

It looks like the CDO implementation on the machine cannot
access the 
mail server.

You config is fine for accessing an unauthenticated mail relay.

Can you try telneting directly into your mail server from the box
running your app:

  telnet madrid 25

Type in "HELO" the server should respond with some helpful message.
Type "QUIT" to exit. Does this work?
Have you tried specifying the smtpHost as a fully qualified
domain name?
or as an IP address? It may be that the CDO library cannot
resolve the 
name.

Are you running any local firewall software that may be blocking
outbound connections, for some or all users or applications?

There seems to be several other people having the same problem with
various fixes discussed here:


http://www.google.co.uk/search?q=transport+failed+to+connect+to+the+se 
rv
er+CDO

Nicko


-----Original Message-----
From: Baron Schwartz [mailto:[EMAIL PROTECTED]
Sent: 21 March 2005 16:57
To: [email protected]
Subject: SmtpAppender not working

Hi,

I've searched the web and read the manual and some of the
code, but 
feel free to point me somewhere there's an answer... I can't find
much on this.

My SmtpAppender isn't able to connect to the smtpHost.  I'm on
Windows using MS framework v1.1.  Here's my config file
([EMAIL PROTECTED] 
is bogus -- I'm using a real value), test code, and the error I'm
getting in the console window when the log fails to
email. The SMTP
server, madrid, is an open relay inside our firewall,
which requires 
no authentication or anything.
I send mail with it from a bunch of other apps.

One thing I did notice, is that apparently there are some other
parameters I could be putting in the config file, but I'm
not sure 
what they should be (the example config seems to be incomplete).
Starting at SmtpAppender.cs, and looking at its
properties, it looks 
like username, password etc *could* be put in the config file.  I
didn't read through enough of the code to determine what the
parameters would be named, because they wouldn't be necessary for
this application, but if someone points me to how I can
find it out 
(short of stepping through the code) I'm happy to update the
example, or augment it with a more complete example.

Thanks for any help.

--- Snip ---
<?xml version="1.0" encoding="utf-8" ?> <configuration>
    <configSections>
        <section name="log4net"
type="log4net.Config.Log4NetConfigurationSectionHandler,
log4net" /> 
    </configSections>
    <log4net>
        <appender name="SmtpAppender"
type="log4net.Appender.SmtpAppender">
            <to value="[EMAIL PROTECTED]" />
            <from value="[EMAIL PROTECTED]" />
            <subject value="Baaaaad error" />
            <smtpHost value="madrid" />
            <bufferSize value="4" />
            <lossy value="true" />
            <evaluator type="log4net.Core.LevelEvaluator">
                <threshold value="WARN"/>
            </evaluator>
            <layout type="log4net.Layout.PatternLayout">
                <conversionPattern value="%-5p %-20t %d
%c line %L%n 
%m%n" />
            </layout>
        </appender>
        <root>
            <appender-ref ref="SmtpAppender" />
        </root>
    </log4net>
    <appSettings>
    </appSettings>
</configuration>
--- Snip ---
using System;
using log4net;
using log4net.Config;
namespace TestHarness {
    public class TestHarness {
        static readonly ILog log =
LogManager.GetLogger(typeof(TestHarness));
        public static void Main(string[] args) {
            XmlConfigurator.Configure();
            log.Warn("hey, this is an error!");
        }
    }
}
--- Snip ---
log4net:ERROR [SmtpAppender] Error occurred while sending e-mail
notification.
System.Web.HttpException: Could not access 'CDO.Message'
object. ---> System.Ref
lection.TargetInvocationException: Exception has been
thrown by the 
target of an  invocation. --->
System.Runtime.InteropServices.COMException
(0x80040213): The
transport failed to connect to the server.

   --- End of inner exception stack trace ---
   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, Bind er binder, Object target, Object[] args,
ParameterModifier[] modifiers, CultureI nfo culture, String[]
namedParameters)
   at System.Type.InvokeMember(String name, BindingFlags
invokeAttr, 
Binder bind er, Object target, Object[] args)
   at System.Web.Mail.LateBoundAccessHelper.CallMethod(Type
type, Object obj, St ring methodName, Object[] args)
   at System.Web.Mail.LateBoundAccessHelper.CallMethod(Object
obj, String method Name, Object[] args)
   --- End of inner exception stack trace ---
   at System.Web.Mail.LateBoundAccessHelper.CallMethod(Object
obj, String method Name, Object[] args)
   at System.Web.Mail.CdoSysHelper.Send(MailMessage message)
   at System.Web.Mail.SmtpMail.Send(MailMessage message)
   at log4net.Appender.SmtpAppender.SendBuffer(LoggingEvent[]
events)






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