Archives August 2006

Troubleshooting 421 4.0.0 error


I hope this may be useful to someone. I have just spent a couple of hours troubleshooting the above error message which was occuring when we sent mail to our company banker.

I appears that others are having similar problems see the thread here:

Anyhow, I thought I would list my troubleshooting steps.

On being told that people couldn’t send mail to the recipient, I proceded as follows:

First I looked at the queues on the Exchange server and located the mail. It was set to retry and had been that way for a day or so.

I next checked the error message presented in the queue viewer which was as below:

“The connection was dropped by the remote host”

I then restarted the SMTP service to see if that would get things moving. As expected, it didn’t!

Having done this I then used nslookup to lookup the MX records for the problem domain. I did this by first setting nslookup to search for MX records using the command:

Set type=mx

then entering the domain.

Once I had the mail servers for the domain I new DNS was working so I then moved on and checked the SMTP logs by going to:

Start/Run/ and typing logfiles.

Then I located the SMTPSVC1 folder and copied the latest log to my PC

I opened the log using Excel and converted the log to columns using?a space delimiter in the wizard.

I then filtered the log to only show the domain in question. This showed that many connection attempts were made but all failed with a “421.4.0.0 Server error” message.

Having established this I tried to telnet to the mail server from my Exchange server and then from another box. Both connection were refused in the same way.

Given the immediacy of the connection drop either we were on a block list or connection filter, or perhaps we were missing a PTR record.

My next step is to get the relevant people to setup the PTR records which is not currently there. I believe it is likely that this will then allow mail to flow.

I have also changed the way the SMTP server announces itself in the advanced section of the delivery tab on the SMTP Virtual Server so that it now announces itself using the same address as the MX record.

I will report back soon with progress.




Adding pictures and links to forum posts

Hi All,

After Conroyd mentioned he had problems with adding links and pictures to posts a while ago, I have now finally found some time to do some testing of this.

Using a standard user account, I created a post in the miscellaneous forum section which you can see from the link below:

In order to create the links use the small globe and chain icon on the toolbar.

To add pictures you need to switch to html mode using the button at the bottom of the entry box and then enter code similar to the?following:” width=200>

Note you must link to a picture hosted elsewhere as we don’t have space to host pictures on the site.



A New Way to blog…

Having finally managed to get a break from work this week (I believe it is called a holiday!) I have had some time to catch up with some developments in the Internet Community.

One of my favorite is this new way of blogging. Called Windows Live Writer, it is a beta application which can be found here:

Basically it allows you to prepare and then upload posts from an app on your machine as opposed to simply using the web interface of your blog. Although it is perhaps not a fully featured as Word 2007 it is a dedicated app for blogging and therefore maybe simply and more focussed.

I hope you find this interesting.



Errors on the Site


This is by way of an appology; I have just noticed that the articles and th links section were not working.

This was caused by not updating the path to the relevant ASPX files when moving to the host server.

Sorry I didn’t notice this sooner.



Post times

Just to let people know.

If you want your posts to appear at the correct time rather than the server time (EST) then you need to setup your time zone for your user account.

This can be done in your profile.