Incoming links not recognized from e-mails?

To understand: is this because of performance or other reasons? What’s interesting is that apparently Microsoft Word documents are scanned - is this because Word documents are (somewhat) similar to RTF?

Would you consider adding indexing to .eml files? Otherwise I would highly appreciate if you have a suggestion what would be the best option to create many-to-many links between items including e-mails Problems creating (many-to-many) relations using x-devonthink-item links - thanks!