Sometimes Subscribers complain. This is what it means in your account.
"Complained" means the Subscriber marked an email you sent as spam.
Once a Subscriber marks an email as spam from their inbox, they are both marked as Complained as well as Unsubscribed from your list. From there, they will not receive anymore emails from you.
You'll see this Complained status either in the Subscriber's profile, above their email address, to the left of Email History:
Or you'll see Complained when you are searching for a Subscriber:
NOTE: Sometimes it's an accident. If it was an unintentional unsubscribe, and your Subscriber reached out to you and gave you written consent this is what happened, let us know! We can help.
Am I paying for Complained Subscribers?
The good news is that Complained Subscribers do not count against your list total, or toward your bill. We only want to charge you for those Subscribers that you can actually email!
So, no action needs to be taken with them. You don't need to worry about deleting them.
Check the email
You can see which email was marked as spam by going to the Subscriber's profile, and looking at their Email History.
In their email history, you will see the subject lines of emails you've sent to them. Under one of those subject lines will be information from which email they unsubscribed.