An SQS queue has a redrive policy with maxReceiveCount: 5 pointing at a DLQ. When does a message move to the DLQ?

SQS counts how many times a message is received. Each time a consumer gets the message but does not delete it before the visibility timeout ends, the count goes up. The visibility timeout is the time the message stays hidden from other consumers. Once the count goes over maxReceiveCount, SQS moves the message to the DLQ.

"After 5 different consumers have read it, even if one deleted it" is wrong. A deleted message is gone for good, so it never reaches the DLQ. "After it has been in the queue for 5 minutes" is also wrong, because SQS counts receives, not time.