When you import addresses into Direct Mail, they are added to the group that is selected in Direct Mail. You can see which group is selected by looking at the source list on the left-hand side of the window. You can control the way the imported addresses are added to the group by selecting an import mode. There are two modes:
Merge into Group
This is the default. In Merge mode, if you import an address that already exists in the destination group, then you will asked if you want to keep the old address, replace it with the new one, or keep both.
For example, if your group had the following address in it:
one@example.com
…and you imported this list:
one@example.com
two@example.com
…then your group would look like this after the import was complete:
one@example.com
two@example.com
Replace Group
Replace mode works exactly like Merge mode, with one important difference. After the import is complete, addresses in the group that were not just imported will be removed.
For example, if your group had the following addresses in it:
one@example.com
two@example.com
…and you imported this list:
one@example.com
…then your group would look like this after the import was complete:
one@example.com
When to Use "Replace Group" Mode
Each address in Direct Mail has a history attached to it (how many times it has been sent to, how many opens, clicks, unsubscribes, etc.). When you delete an address, that history is lost. If you use import merge modes, however, Direct Mail can make sure that history stays attached to the address.
For example, let's say you have exported your client list from another program and want to import it into Direct Mail. You have already done this process once before and now want to re-import the list into Direct Mail. You don't want to lose the history for the contacts in Direct Mail, but you also know that some of the clients you imported before no longer appear on your current client list and should be removed. In this case, you would use the "Replace Group" merge mode. Direct Mail will make sure that any contacts you already imported are simply updated with the new client list information, and will also make sure that any contacts that don't appear on the new client list are removed from the group.