We don't have a Plug-In for Apple Mail client.
However, using the Apple mail client, you can still sync your email by copying the email to the "Copy to CRM" folder which gets created in your gmail account. The background process will sync the email. It can also be done on the phone mail client.
Calendar sync is a background process so they will show up in your Apple Calendar app.
Hope that helps.
Sugar Connect Product Manager
Senior Director Product Management