@lynnesbian @sophia I firmly disagree. Here are the reasons why Gmail is #FOSS:
* No vendor lock in, you can send messages to people who do not use gmail
* No lock in in the UI either, you can use Thunderbird if you choose to and Gmail would still work
* Not only can you view the source code but you can also save it (Ctrl+S) and upload it to your cloud. Giving you the opportunity to have your own Gmail.
* It starts with a G, like GNU

All of this combined is more than enough to call Gmail #FOSS