Harrison/msg files (#2375)

Co-authored-by: Sahil Masand <masand.sahil@gmail.com>
Co-authored-by: Sahil Masand <masands@cbh.com.au>

tests/integration_tests/document_loaders/test_email.py

@@ -0,0 +1,20 @@
+from pathlib import Path
+
+from langchain.document_loaders import OutlookMessageLoader
+
+
+def test_outlook_message_loader() -> None:
+    """Test OutlookMessageLoader."""
+    file_path = Path(__file__).parent.parent / "examples/hello.msg"
+    loader = OutlookMessageLoader(str(file_path))
+    docs = loader.load()
+
+    assert len(docs) == 1
+    assert docs[0].metadata["subject"] == "Test for TIF files"
+    assert docs[0].metadata["sender"] == "Brian Zhou <brizhou@gmail.com>"
+    assert docs[0].metadata["date"] == "Mon, 18 Nov 2013 16:26:24 +0800"
+    assert docs[0].page_content == (
+        "This is a test email to experiment with the MS Outlook MSG "
+        "Extractor\r\n\r\n\r\n-- \r\n\r\n\r\nKind regards"
+        "\r\n\r\n\r\n\r\n\r\nBrian Zhou\r\n\r\n"
+    )