I was enthusiastic about Bynari when I first read about it, but after downloading it and using it for a short time, I realized that it didn't work well with the IMAP server integrated with SME. I would advise setting up a seperate test email account that you can use on your SME server and only use that account for testing.
The most promising features of Bynari are the address book being stored on the server, calendar for those that use it, sent mail being placed on the server automatically, trash bin working as it should.
Bynari with a way to deliver mail to multiple MTA's with one domain and no subdomains along with Samba BDC support would open SME up to a much larger audience. IMHO