What are the different statuses of a message campaign in Vtiger CRM?

Message campaigns in Vtiger CRM go through several statuses that indicate their current progress:

• Draft: The campaign is created (or being created) and saved, but not yet sent.
• Queued: The campaign is in the queue and will be sent shortly.
• Sending: The campaign is currently being sent to recipients.
• Sent: The campaign has been successfully sent to the service provider.
• Completed: The campaign is marked as completed when all messages are either successfully delivered or their delivery has failed.