1.6.7 is the latest live version.
Do you have access to server email to see if things were deferred or if there was an error?
Without seeing the email setup page, I’m not sure I can be more help. If you can send a screenshot as a direct message on our Facebook page so your information isn’t listed publicly, I could take a look, but I don’t want those email addresses being put up publicly if we don’t have to!
As far as using the newer version, if you back up your older version Book a Room plugin folders and database, you can try removing the old version’s folder and dropping in the unzipped test version. The new version uses the same DB with the addition of a new table so if you have to go back to the previous version, you should be okay.
But, again, back up everything! THis is still being tested and there have been a few bug fixes already.