I'm guessing AWS4C might have the old request format that may not supported anymore (I haven't tried).
You can try something like this:
http://sqs.us-east-1.amazonaws.com/123456789012/queue1?Action=SendMessage&MessageBody=Your%20Message%20Text&AWSAccessKeyId=AKIAIOSFODNN7EXAMPLE&Version=2012-11-05&Expires=2008-02-10T12:00:00Z&Signature=lBP67vCvGlDMBQ1dofZxg8E8SUEXAMPLE&SignatureVersion=2&SignatureMethod=HmacSHA256
For making a request to the us-east-1
SQS region. You can see more information in the latest docs here: http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/MakingRequests_MakingQueryRequestsArticle.html