Fix wrong mail displayed in IMAP preview

1. install and configure imap connector
2. click Check Email
3. open the first mail
4. click preview (the eye icon)
5. a preview of the mail body is displayed
6. go back to the mail headers
7. open another mail
8. click preview (the eye icon)
9. the same mail is displayed
10. click More / Preview
11. the right mail is displayed

In the mail header list, clicking the eye icon works fine though.