Mail with attachment referenced from html shows the paper clip

Receiving emails that have an image referenced from html (for example in the mailcard), not stated as inline but with Content-ID, shows the paperclip on the grid as if there were an attached file that is actually as an linline referenced image.
If you perform a search on messages with attachments, all these emails are also shown but they actually just have inline images.
On message view the mail correctly shows the inline image and does not show the attachemnt (because it could discover that it were referenced from html, so actually inline)

Steps to reproduce:

• import the attached email

Expected behaviour:

• the email does not contain attached files on message view and the paper clip on the grid is not shown

Actual behaviour:

• the email does not contain attached files on message view, but the paper clip on the grid is shown

Note: on Thunderbird this type of mail is shown without an attachment