POM picks up the contacts from a contact list for dialing in advance.

Hence, if you replace an existing contact list with a new contact list in a running campaign, or if the existing contact list is updated, then in addition to the new contacts, POM also dials the contacts that are already picked up for dialing from the old contact list.

If you remove a contact list from a campaign, POM dials the contacts that are already picked up for dialing from the removed contact list.