I don't know about software, but most likely it would cost you.
As for your approach with Netscape and another username, which means a new profile, there is a very easy way to solve the problem. Locate your User folder on the Hard Drive, and the old profile|Mail|account name. Right click on the Inbox file, and select Copy, and then Paste in an empty are. Right click|Rename the file to anything other than Inbox. This file will contain all your Inbox mail, and you can right click|copy the renamed file, and paste into the new username folder. You do everything with Netscape closed, and ignore the .snm file. When you open Netscape, the next time you will find your mail, but in the renamed file.
You don't have to check the original message, but only the the Inbox file. All your messages are there. Now, if you have a problem with the renamed file showing only a limited number of messages, it is a different story.
You can have as many subfolders into Netscape, that there should be no reason for this achrobatics. I right click on the Inbox folder, in Netscape mail, and select New Profile, and name it.
It is a pain, if start with 700 e-mail, but not so bad if you split them up.
I panic if my Inbox has over 40 messages.
And, finally, if you really want to go to OE ( don't) this is from Microsoft.
Import Messages from Other E-Mail Programs
Using the Outlook Express Import Wizard, you can easily import e-mail messages from a variety of popular Internet e-mail programs, such as Netscape Communicator and Eudora, as well as from Exchange Server and Outlook.
On the File menu, point to Import, and then click Messages.
Select the e-mail program you want to import messages from, and then click Next.
Verify the location of your messages, and then click Next.
Choose All folders to import all the messages, and then click Next. You can also choose Selected Folders to import messages from one or more folders.
Note: If you are unsure which e-mail program and version you want to import messages from, start the e-mail program. On the Help menu, select About and check the information for program and version.
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