I used the DRS Gmail Backup Tool to migrate my Gmail emails. I did not know how to export emails using this application. But the software has a very interactive user interface such that I migrate all of my Gmail emails in no time. Thanks to developers for giving us this simple yet effective software.
Tip for consumers: I would love to recommend the advanced tools of DRS Softech as they are specially designed for a novice user. You should definitely give it a try.