In the bulk mail management section, I can create a message and filter members without any issues.  But once I send the bulk mail, the sent to field is set to 0, and time taken says "Not Started".  Please see attached image for an example of my issue.

I believe @HAINAngel may have a similar issue.

Please ensure that your background processes are functioning in ACP -> System -> Dashboard -> Background Processes. If they are running slowly, this may mean that you have limited traffic on your community may need to consider changing your background processes to run on Cron in ACP -> System -> Advanced Configuration. If you are running these via Cron, something is wrong with cron on your server so you will need to contact your hosting provider.

Ok understood.  I am rebuilding my achievements right now, and it appears that processes run via a queue (not asynchronously) which would explain the bottleneck.  Thanks for the clarification.