GroupWise knows a lot of error codes in its logs and most of them are not really good documented. Also for some documented error codes some more background details would be helpful and best practices how to handle such problems.
For example there is the well known D107 lost attachment error which can be solved by clipping the pointer with GWCheck and ATTCLIP. But why and when an attachment gets lost? Should ATTCLIP become a "standard" for maintenance runs?
Also interesting question is which error messages in verbose log mode are just informational and can be ignored.

So perhaps a webinar with best practices for logging and troubleshooting would be good. If somebody have more examples please feel free to add them in comments