The Gmail (and calendar) notifier on the Mac are default sending your password as plain text over the internet. You can however change this in a hidden setting dialog to send all data over https by holding down the Command and Option key and pulling down the Notifier menu, then click the Preferences option and a dialog will pop-up. Now enter SecureAlways (exactly as shown) in the Key-field and put a 1 in the Value-field. Click Set and restart the Notifier. All communications with the Google servers will be secure from now on!