Send as email
JabRef allows you to send entries to third parties via email.
How to send as e-mail
Select one or multiple entries
Choose Tools → Send as email in the menu
This will open your default email application and automatically paste the entries in their raw BibTeX format. Once your correspondents have received the email, they will be able to directly copy and paste the entries into JabRef (or use them in other ways).
How to attach linked files of entries to your email
Once Send as email is pressed, JabRef will also automatically open the folder of attached files, as long as the option automatically open folders of attached files is enabled at File → Preferences → External programs → Sending of emails. Attaching these files to your email is possible by dragging and dropping the PDF files into your favorite email application.