Question : Best way to monitor my outgoing mail errors from an IIS webserver

I manage several (10) IIS webservers which use IIS SMTP. We've recently reversed out policy of outsourcing our email delivary to a 3rd party, something that wasn't very good as even if emails did bounce, we wouldn't see the reports. Each server hosts 40-80 ecommerce stores with mailing and mass-mailing functionality.

Now the webservers mail directly they do okay, however there are 3 main types of errors I find in the event logs for SMTP:

1.
4000
Message delivery to the remote domain 'examplel.com' failed for the following reason: Unable to bind to the destination server in DNS.

2.
4000
Message delivery to the remote domain 'example.com' failed for the following reason: Unable to deliver the message because the destination address was misconfigured as a mail loop.

3.
4006
Message delivery to the host '11.11.11.11 failed while delivering to the remote domain 'example.com'' for the following reason: The connection was dropped by the remote host.

Now #1 is basically an invalid or out of date address so as far as I'm aware I can ignore them.

#2 Is saying 'this mail server is misconfigured or messed up

#3 Is saying the mail was rejected, maybe they think we're spammers for example.

In the case of #2, I need to check these in case these are our client's mail servers. Very often our clients will send emails from [email protected] to [email protected] from the store. If example.com can't receive emails, people can't reply to that email address to opt out of mass mails meaning that the customers are effectively spamming! I need a way to export my event logs of this nature, and generate a list of misconfigured domains as a result for follow up.

In the case of #3, very often I cannot reproduce these issues. If it passed telnet 11.11.11.11 25 and I don't get an error, is there anything I can do? Still occasionlly their mail server will tell me 'we are blocking you!' so this is still interesting information and I can appeal etc.

Again, I need to export the data of events of this type for automated testing and reporting for follow up where necessary.

Or is there a suitable IIS SMTP log analyser that'd do all this for me?

Or should I bite the bullet and configure a proper dedicated mail server with all the bells and whistles?

Answer : Best way to monitor my outgoing mail errors from an IIS webserver

We use BMC patrol which has an option to just search event log for a specific word to trigger an alert (which copies the error and time into an email and sends it to me). I just search for "fail" and "error", which is sufficient to get 99% of all interesting log entries.