diff --git a/submitter/submission.py b/submitter/submission.py
index 93eee07..d5dda5c 100644
--- a/submitter/submission.py
+++ b/submitter/submission.py
@@ -188,7 +188,7 @@ def submit(self, client):
             self.result_error_message(e.message, getattr(e, "dspace_error", None))
             clean_up_partial_success(client, item)
         except Exception as e:
-            logger.error(
+            logger.exception(
                 "Unexpected exception, aborting DSpace Submission Service processing"
             )
             raise e
diff --git a/tests/conftest.py b/tests/conftest.py
index e6ac817..0a75732 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -52,6 +52,15 @@ def test_aws_user(aws_credentials):
 
 @pytest.fixture(scope="function")
 def mocked_dspace():
+    """The following mock responses from DSpace based on the URL of the request.
+
+    Fixtures below that prepare an SQS message, where specific collections or bitstreams
+    are included, will utilize these mocked responses from DSpace.
+
+    EXAMPLE: fixture 'input_message_item_post_dspace_timeout' sets collection
+    "CollectionHandle: 0000/collection03".  This aligns with a URL defined here, and will
+    therefore throw a requests.exceptions.ConnectTimeout exception to test against.
+    """
     with requests_mock.Mocker() as m:
         m.post(
             "mock://dspace.edu/rest/login",
@@ -69,6 +78,12 @@ def mocked_dspace():
             "mock://dspace.edu/rest/handle/0000/collection03",
             exc=exceptions.ConnectTimeout,
         )
+        m.get(
+            "mock://dspace.edu/rest/handle/0000/collection04",
+            exc=exceptions.RequestException(
+                "Catastrophic error before or during request!  No response to parse."
+            ),
+        )
         m.get(
             "mock://dspace.edu/rest/handle/0000/not-a-collection",
             status_code=404,
@@ -347,6 +362,30 @@ def input_message_bitstream_file_open_error(mocked_sqs):
     yield message
 
 
+@pytest.fixture
+def input_message_item_post_dspace_generic_500_error(mocked_sqs):
+    queue = mocked_sqs.get_queue_by_name(QueueName="empty_input_queue")
+    queue.send_message(
+        MessageAttributes=test_attributes,
+        MessageBody=json.dumps(
+            {
+                "SubmissionSystem": "DSpace@MIT",
+                "CollectionHandle": "0000/collection04",
+                "MetadataLocation": "tests/fixtures/test-item-metadata.json",
+                "Files": [
+                    {
+                        "BitstreamName": "test-file-01.pdf",
+                        "FileLocation": "tests/fixtures/test-file-01.pdf",
+                        "BitstreamDescription": "A test bitstream",
+                    }
+                ],
+            }
+        ),
+    )
+    message = queue.receive_messages(MessageAttributeNames=["All"])[0]
+    yield message
+
+
 @pytest.fixture
 def input_message_bitstream_dspace_post_error(mocked_sqs):
     queue = mocked_sqs.get_queue_by_name(QueueName="empty_input_queue")
diff --git a/tests/test_submission.py b/tests/test_submission.py
index d3ae542..e4bc598 100644
--- a/tests/test_submission.py
+++ b/tests/test_submission.py
@@ -4,6 +4,7 @@
 import pytest
 from dspace import Bitstream, Item
 from freezegun import freeze_time
+from requests.exceptions import RequestException
 
 from submitter import errors
 from submitter.submission import Submission, prettify
@@ -181,3 +182,26 @@ def test_submit_bitstream_post_dspace_error(
         "Error occurred while posting bitstream 'test-file-01.pdf' to item in DSpace. "
         "Item '0000/item02' and any bitstreams already posted to it will be deleted"
     )
+
+
+def test_submit_dspace_unknown_api_error_logs_exception_and_raises_error(
+    caplog,
+    mocked_dspace,
+    test_client,
+    input_message_item_post_dspace_generic_500_error,
+):
+    submission = Submission.from_message(
+        input_message_item_post_dspace_generic_500_error
+    )
+    with pytest.raises(RequestException):
+        submission.submit(test_client)
+    # assert actual encountered exception is logged (for debugging purposes)
+    assert (
+        "Catastrophic error before or during request!  No response to parse."
+        in caplog.text
+    )
+    # assert unhandled exception encountered in submit flow logged
+    assert (
+        "Unexpected exception, aborting DSpace Submission Service processing"
+        in caplog.text
+    )