Marketing → Campaigns lists campaigns, newest first, 10 a page. Search by name or subject; filter by segment and status. The Trash tab holds deleted ones.
Status
Draft → Scheduled → Sending → Sent, or Failed. The only way back is Cancel schedule (Scheduled → Draft). A sent or failed campaign cannot be sent again or edited: make a new one. Only drafts can be edited, and the server enforces it.
The form
Name, Email subject, Preheader, Segment (blank means everyone), Audience scope, an optional SMS body (up to 1,600 characters, only if your SMS provider can send marketing messages), and an optional schedule window. The email body is not in this form: open it with the envelope icon (Email Studio). Use {{firstName}} and {{email}} to personalise; SMS is not personalised.
Send and Start campaign
For a draft with no future start date the button reads Send and sends at once, ignoring any dates. With a future start date it reads Start campaign and arms the schedule. Both ask for confirmation, because a sent email cannot be recalled. The campaign needs email content, a segment that is not in Trash, a real sender (see Settings), and at least one deliverable recipient, otherwise it stays a draft and says why.
Scheduling
A scheduler checks every minute. If the window's end has passed when it gets to the campaign, the campaign becomes Failed and is never sent late. The end date without a start date is ignored.
SMS
A separate SMS button, on draft rows only, can be pressed once per campaign. It sends inside the request, costs money per message and reaches every recipient with a phone number. Once the email is scheduled or sent, SMS can no longer be sent from the page.
Trash
Delete moves a campaign to Trash and keeps its history; Restore brings it back. Delete permanently needs its own permission and is refused when the campaign has any delivery or engagement record. Trashing a sending campaign does not stop its queued mail.