Now that you've done the pre-move set-up for your newsletter, and you've gotten your new service "home" all ready, it's time to do the sorting and packing. In this step you'll want to:
1. Export your mailing list from your current provider. Many services allow you to export to some sort of format that Microsoft Excel can read. If the way to export is not immediately apparent, check the help files. You'll want to get your export file, and I'd also recommend making a permanent backup of this file at this time as well.
2. Clean up your export file. If your current provider offers coding of your mailing list, according to open rate, activity level, or even just whether they are still subscribed or if their email address is bouncing, this is a good time to do some cleanup of the list. Just move active clients over to the new service.
3. Import your mailing list file to the new service. Be aware that if your new service requires opt-in confirmation, your clients will get this notification immediately – so be sure you've told them about the move, done your set-up of your new opt-in messages, and tested the new mailing list service before doing this step. If everything's ready, move your existing clients over to the new service.