Follow these directions if you are transitioning off an existing email service onto the Iterable platform. This is assuming you will be importing users into Iterable through the UI with CSV list uploads.
1. Export all active users (users who have neither hardbounced nor unsubscribed) from existing service. If you were using Mailchimp, you will need to export all lists, since Mailchimp does not have the concept of a master list that includes all users across all lists.
2. Import your list(s) of active users into Iterable by going to Users --> Import List. Import these as standard lists.
3. Export all hard bounces and unsubscribes from existing service. Hard bounces are old, outdated or misspelled email addresses that are no longer in use.
4. In Iterable, channel unsubscribe hard bounced and unsubscribed emails by going to Users--> Lists --> Channel Unsubscribe Users.
Unsubscribe them from either all channels or all marketing channels. Unsubscribe them from all channels if you do not want them to receive any communication from you. Unsubscribe them from just the marketing channels if you do not want them to receive any promotional messages, but still want them to receive transactional messages.