Cannot post to SQS queue that is not owned by Caesar

[hughdickinson]

Caesar seems unable to send messages to SQS queues created using another AWS count, even if access to that queue by Caesar is granted using an access policy modelled on the one used for queues that are owned by Caesar. e.g. (with potentially sensitive strings redacted)

{
  "Version": "2012-10-17",
  "Id": "arn:aws:sqs:us-east-1:<non_caesar_owner_arn>:<queue_name>/SQSDefaultPolicy",
  "Statement": [
    {
      "Sid": "33B59DA5-0F94-443B-8904-E652B8FFEA73",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::<non_caesar_owner_arn>:root"
      },
      "Action": "SQS:*",
      "Resource": "arn:aws:sqs:us-east-1:<non_caesar_owner_arn>:<queue_name>"
    },
    {
      "Sid": "8C9F2711-6FA7-4C7B-98B2-A86395C80417",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::<caesar_arn>:user/caesar"
      },
      "Action": "SQS:*",
      "Resource": "arn:aws:sqs:us-east-1:<non_caesar_owner_arn>:<queue_name>"
    }
  ]
}

Note that the Sids are auto-generated UUIDs and the Id format is modelled on the policy used for queues that are owned by Caesar. In fact it can be any string and is only used for naming purposes.

[lcjohnso]

@zwolf -- Do you have an ideas why POSTs to external SQS queues would not be successful?