Activity Messenger Help Center Building a master list to combine multiple lists Build a master list when the same message must reach people from several lists or forms. Choose which sources to include and which to exclude, then review the resulting audience before sending. Go to the Lists section and select Create. Then choose the Master List option, choose a name and select Create. Open the new Master List. Click the + button with the people icon to add a source. Choose an existing list or a form, then select the source you want to include. Repeat this step to add another source, such as your uploaded CSV list and a registration form. The + button inside a regular CSV distribution list adds an individual recipient; it does not add a list or form as a source. To combine sources, first create and open a Master List, then use its + button. You can add multiple sources. To exclude people from a source, use the − button and choose the list to remove from the final audience. Master Lists update automatically when new people submit a source form or register for a source class. If a recipient appears in more than one source, they appear only once in the final list. Contacts with the same email address but different mobile numbers are treated as distinct recipients; Activity Messenger sends the same email to a person only once. Next: Send your first email or SMS