unstructured/example-docs/eml/signed-doc.p7s

MIME-Version: 1.0
Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg="sha-256"; boundary="----DA7C0B64AB4D78BAFBED70C0FA340877"

This is an S/MIME signed message

------DA7C0B64AB4D78BAFBED70C0FA340877
This is a test

------DA7C0B64AB4D78BAFBED70C0FA340877
Content-Type: application/x-pkcs7-signature; name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7s"

<SIGNATURE>

------DA7C0B64AB4D78BAFBED70C0FA340877--
enhancement: process `.p7s` files with `partition_email` (#2521) ### Summary Closes #2489, which reported an inability to process `.p7s` files. PR implements two changes: - If the user selected content type for the email is not available and there is another valid content type available, fall back to the other valid content type. - For signed message, extract the signature and add it to the metadata ### Testing ```python from unstructured.partition.auto import partition filename = "example-docs/eml/signed-doc.p7s" elements = partition(filename=filename) # should get a message about fall back logic print(elements[0]) # "This is a test" elements[0].metadata.to_dict() # Will see the signature ``` 2024-02-07 17:31:49 -05:00			`MIME-Version: 1.0`
			`Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg="sha-256"; boundary="----DA7C0B64AB4D78BAFBED70C0FA340877"`

			`This is an S/MIME signed message`

			`------DA7C0B64AB4D78BAFBED70C0FA340877`
			`This is a test`

			`------DA7C0B64AB4D78BAFBED70C0FA340877`
			`Content-Type: application/x-pkcs7-signature; name="smime.p7s"`
			`Content-Transfer-Encoding: base64`
			`Content-Disposition: attachment; filename="smime.p7s"`

			`<SIGNATURE>`

			`------DA7C0B64AB4D78BAFBED70C0FA340877--`