Tips for importing old email to Gmail

When I switched to Gmail more than a year ago, I still had a significant amount of old email stored with my old address. Because I keep messages for a long time and like to frequently search them, I wanted to move my old email to Gmail so it would all be in one place and I could access it on any device, including my mobile phone.

In the end, the move went smoothly, but I picked up a couple of tips along the way that I thought were worth sharing.