How to work with foreign file formats exchanged via attachemnts (email, chat whatever) with any program (office suite or any other editor of anything):
- You receive a file in a foreign file format. Open the attachment. It will be a read-only version until you save your own working copy in your application’s native file format.
- As a last step after editing the file, you convert your working copy to the foreign file format and send this file back to your co-editor.
- Next time you get another instance of the same document, you can repeat step 1) overwriting the old working copy or adding another version of it.
Both of you still have all the other versions as attachments in your inbox and outbox. And the co-editor should keep his working copy in the native file format of his application.
I did not mention Word or Writer. It applies to spreadsheets, presentations, musik files, movies, desktop publishing and all kinds of creative work on shared documents. Always edit your work in the native file format of the application you are using.
P.S. simply store the received docx with all the comments as the new working copy in odt format.