MXTrace simulates delivery of a message, using the same code-path as the shipping NetMail (previously named NIMS) product. It allows the administrator to diagnose why a message might not get delivered. It has two lookup options:

1. DNS Trace
2. DNS & SMTP Trace

The DNS trace option only performs a DNS lookup using the *NetMail* resolver. It will display all MX addresses in the order that NetMail would use them for delivery. You need to specify the RFC822-style domain part of an address. Thisis usually the hostname, but since constructs like peter@[137.65.47.150] are also possible in the email world, you can enter the [137.65.47.150] address as the hostname as well.

This option will do the same lookup as the DNS Trace option, but it will additionally simulate delivery of a fictional message to the address. For this option you need to enter the sender address and recipient address, just like in your email app. This allows you to diagnose remote side problems that are based on a sender or recipient address. You can then watch it deliver your message. Don't worry, it will not actually drop off a message, it will only send the first three SMTP commands (EHLO & HELO/MAIL FROM/RCPT TO), no DATA will be sent nor will the remote recipient get any kind of indication that such a test was run. You can watch the commands being exchanged, and you will be presented with the result of the delivery process. Unless you force it to use all exchangers, the delivery simulation process will stop once it looks like delivery would be successful.

You'll also get some diagnostic details about the remote SMTP server.

This tool will not catch problems that are related to the DATA command on the remote system (i.e. yahoo.com timing out on the connection while data is being sent to them; or servers that run out of diskspace while receiving data).

We wrote it to run on the server because that allows to also detect problemsrelated to your IP address, e.g. your host is blocked by a RBL list, or yourserver has routing problems, etc.

Just because MXTrace shows that delivery is possible it does not guaranteethat NetMail can deliver; successful delivery might depend on the time when delivery is attempted; a server might be busy when NetMail tried but was not busy when you ran MXTrace.

You MUST have NetMail (NIMS) running when running this tool, since it uses the actual NetMail functions to do the trace.

This utility is provided as is, with no warranty whatsoever. To the best of my knowledge it performs the task it was written for. If it doesn't do what you want it to do, we will not fix or change anything. We are not responsible for damage.