Tips for troubleshooting SMTP delivery failures.
1. Reading and understanding Delivery Failure Notifications
Read the delivery failure notification. It's a zen thing: the answer to the question is in the question. SMTP servers by default notify the sender of failed messages, so someone will receive a failure. If you don't have a failure notification to look at then try to get a fax or other hard copy of it.
When you are given external failures to look at ask the sender to provide headers. Depending upon their client they may not see any headers. Usually you can tell a lot about which server has a problem by seeing which was the last server the message arrived at as you trace the path the message took by reading the headers.
For details look up the error code on the RFC 1893 web site which describes the ESMTP protocol.
2. Looking at Full Headers in Notes
In Notes, one way you can see full headers is to export the message in question to a text file.
How to view full headers of a Notes mail message.
You can view the contents of each field on the message (include header fields) by selecting document properties and looking at the field listing tab. An even better method if you want to be able to see all of the headers all in one place is to select the email in the inbox view and then export it to a text file.
1. Select the e-mail message in the Inbox or other view of the mail file.
2. Select File, Export.
3. Pick a location to save and fill in a file name for the exported file. It should be type Structured Text, and it helps to give the file name a .txt extension as this will help it automatically open in Notepad or whatever default text editor you use.
4. In the Structured Text Export dialog box make sure you click the radio button to export only the selected documents, or else you may get more than you bargained for!
Here is a link to the Notes Net post by Maria Helm where I learned how to export the full headers:
3. Performing an NSLookup
For failures citing a problem with the domain you can check the DNS settings of the intended recipient using nslookup. This will query the DNS server for that domain. Set the type to see what is listed for their MX (mail exchanger) record. MX records should not be set to a C name or alias but should be an A record in DNS.
Simple Logic has a nice web based NSLookup tool.
Here is a link to a tehcnote in the Lotus Notes K-base about NSLookup: