How do I add a single contact that is already in the database to a pre-created list?

This customer had a mailing list already created in the Engage section and wanted to manually add additional contacts to it.

Here are the steps for getting this done:

(1) First we have to figure out who is on this mailing list. We do that by going to Engage > View and Modify Mailing list, and then clicking Edit next to the list in question (in this example, that's the Executive Invitation List.) That tells us that the list is based on the Senior Exec segment.

(2) Then we have to figure out what criteria this segment was based on. We would go to Contacts, click on Segments and then View All Segments. Then we'd click Edit next to the segment we're interested in (in this case this was the Senior Exec segment.) That tells us that the segment is based on the Yes value in the Senior Exec Field.

(3) Then we'd look up the contact we want to add to the mailing list by name/email and click Edit next to it.

(4) On the Update Contact screed, we'd find the required field and make the appropriate change. (In this case, this was changing the value in the Senior Exec field to Yes.)

Once you click Update Contact, this email will be added to the correct mailing list.

Of course, if you know what segment the mailing list is based on and what criteria you used to create the segment, you can skip the first two steps.