To be able to use the new mail server you must abandon your previous mail server completely. First you have to set your preferences for the new mail server, after that you must manually move all old mail you want to keep. This guide is meant to help you to move all your old mail. For the images in this document to be accurate you must be using Netscape 7.0 but the principles are the same for many mail clients.
Start by creating a new account according to the following sequence of images.
Note that the field "User Name:" in the slide above is not consistent with the previous slides! If you have done everything correctly it should instead read your username (in this case "vel").
In order to be able to log in you must make some final changes to the new account. Follow the menus in Netscape (Edit->Mail & Newsgroups Account Settings...) and check the box according to this image:
Make sure to manually move all mail in the old account (Inbox and all folders) to the new account. The new folder hierarchy must also be created manually. Select the mail to be moved and then drag and drop them where you want them. Depending on the amount of mail in each folder this might take som time. For about 1,000 messages with an average size of 5kB it will take approximately 15 minutes. Please be patient.
When all mail is moved go to the prefences again (Edit->Mail & Newsgroups Account Settings...), select the old account and choose "Remove Account".
Finally you must change the preferences for sending mail (Edit->Mail & Newsgroups Account Settings...) in accordance to this image:
When a reasonable amount of time has passed and nothing is missing or strange it is highly recommended that you remove all of the old folders in your home directory to recover more space.