Campaigns have statuses which decide if the campaign will run and whether new contacts can be added into it. There are three different campaign statuses.
Campaign will run as normal. Any contact who meets the start conditions will being the campaign immediately. New campaigns need to be made active when ready.
The campaign will run as normal but no new contacts will be allowed to enter until the status is returned to active.
This status is for campaigns that run for only a limited time rather than an ongoing campaign. These campaigns have discount codes that expire, and so that contacts aren't getting old discount codes, the campaign will not let any new contacts in while allowing emails to continue to go out for the duration of the campaign.
Campaign is off. All actions are switched off and no new contacts will be allowed to enter. This is the default status of new campaigns.
A campaign's status can be modified using the status controls at the top of the page:
Please be aware that contacts can still be added into locked and inactive campaigns by an add to campaign action. If the campaign status changes from inactive to locked or active, all contacts in the campaign will continue at the same point as they were at before the status was changed to inactive.