Can I just check:
Are the ‘Finder Comments’ or ‘Annotations’ section the best place for a translator to add a few notes about ‘archived emails’ they are reviewing? Or is there a better place / feature for them to use?
You sure can check 
Either is viable. However…
- Finder comments in the Finder have amore limited number of characters over what DEVONthink can store.
- Annotation files are fine though they’re a separate file.
If you and the translator are using the Pro edition of DEVONthink, it would be possible to add a custom metadata attribute.
Also, the translator could create a document, e.g., rich text, to make notes about each email but contained in one document, e.g.,…
Great thanks for the thoughts - I’ll try the custom metadata attribute - I want to be able to glance through things quickly based on labelling / ranking of the emails, so cycling through the list view and seeing the notes pop up in the meta data would make sense
You’re welcome!