When signing into my Gmail account, Firefox reports that the connection is only "partially encrypted"; Safari, on the other hand, maintains complete encryption.
Gmail accounts are supposedly encrypted when signed in, and in Firefox, that is true when login is successful and the message inbox is displayed (as shown in the blue-highlighted URL field). However, when an individual message is selected and opened for viewing, the URL field becomes highlighted in red and the padlock icon at the bottom right corner of the browser is unlocked, indicating that full encryption has been lost somehow.
I have also accessed my Gmail account in the Safari browser, and so far I have not encountered the same loss of encrypted connection as when using Firefox.
Opaite Mbohovái (2)
Partial encryption means that Firefox detects content on a secure https page that comes from a regular http server. That can be some Ad script or images. Sometimes you can see that in Tools > Page Info > Media.
Safari may act differently in such cases.
Thanks for your answer. I have noticed that whenever I open up a message containing images and/or links from outside Gmail (usually when the message is in html format), the connection becomes partially encrypted.
However, once the connection loses full encryption, it remains in that state even when I open up a pure-text message or when I start composing a message. I find it a little unnerving to try sending notes out when Gmail's URL is highlighted in red. So until Mozilla fixes this (if this is indeed a bug/quirk), I will stick with Safari whenever I need to use Gmail.