Using the GroupWise Import POP3/IMAP tool, there were many issues trying to convert large and complicated Outlook Express Message Stores into GroupWise. The most common error received was "Error number 07: An error occurred while reading from a data file." There were a few suggestions online on how to resolve it, but nothing worked in every situation. Sometimes you could import 1000's of messages with no problems, and sometimes you'd have one folder with 10 messages that you couldn't import to save your life.
The problem has mostly to do with the state of the Outlook Express Message Folders. There are a number of products you can purchase to clean these folders up, but many of them were a crapshoot when it comes to actually solving the problem for the GroupWise Import.
There is a document that thus far has solved the errors for me in every case. In the Microsoft Community there's a document called An Outlook Express basic repair kit:
The document discusses several things to clean up your message store, but the solution that solves the errors listed above in almost every case is the section called Create a New Identity. Basically, the gist of it is you're creating a new message store and then transferring every single message in their corresponding folders to the new messsage store. This cleans up any of the corruption issues that are in the original message store, and thus it allows you to import all of the messages into GroupWise without any issues.
Before using this solution I had purchased a couple of products and tried numerous suggestions to no avail. This solution works every time.
Disclaimer: As with everything else at Cool Solutions, this content is definitely not supported by Novell (so don't even think of calling Support if you try something and it blows up).
It was contributed by a community member and is published "as is." It seems to have worked for at least one person, and might work for you. But please be sure to test, test, test before you do anything drastic with it.