Sending an email to your entire list of contacts is not available by default. You will need to create a segment to group the contacts for a campaign. See the steps below.
- Go to the Contacts Dashboard.
- Choose "Segments" from the left-hand navigation.
- Click the "Create a Regular Segment" button at the top-right.
- Give your segment a name and description.
- Open the "Select a Field" drop-down and search "Email". Select "Email Address (EmailAddr_)".
- Is - set to Not Null