Need help to clear email folder

[JamesMTL]

I have been using MS Office 2007 for years with heavy usage of Outlook. About 2 years ago I rec'd a message that my email folder was full. I was no longer able to use Outlook and I was not able to delete emails as I did need them all. So, I switched to Thunderbird. There are more features in Outlook that I like and require and I would like to know if there is a way to go back to Outlook without deleting any of the emails I still have in there. Can I increase my email folder size or create a new folder while still keeping my old emails in a secondary folder. I guess sort of like partitioning a hard drive..



Any help is appreciated.