Give https://www.pirateship.com/ a try. I'm so glad I found them. They have tons of great features for shipping, including importing and creating batch payments with presets. No more errors when addresses contain more than 40 characters. And no more manually fixing zip codes that start with a zero. Please check them out. Plus, they are TOTALLY FREE TO USE!!!
p.s. I am not affiliated with them. I am just trying to get the word out for those like me that got mad that PayPal changed their multi order shipping process. If you like pirate ship, please pass the word around. Great people to work with