The Easy version of Mail Archiver can archive only 10,000 emails. You can update to the standard version so that you can archive as many emails as you like. Have a look at the comparison chart for the differences between the versions.
There are 3 steps for updating to the standard version:
Then you will get the special update price of $27.95:
You must be registered or you will get an error message. The result is a new window in Finder: Move the database files and additionally change the location in the Data Format section of the Setup. If you don't want to do the Setup again move PlanData.db into user/username/Library/Application Support/Mail Archiver X. The app should not be running when you move the file.