Contact-to-contact email attachments not working

To reproduce.

1. create a contact using an email address that you can check its mailbox

2. access this contact summary screen, click "actions" button

3. click "send an email"

4. attach a reasonable size attachment (< 200kb) and send

5. check the recipients email box, the email arrives, but there is no attachment

Recall this feature working as recently as June 2016, suggest it may be a regression