It doesn't seem like its possible to send email over php in windows without some third party plugin
I'm confused.. Why would it not be possible? "php in Windows" is the confusing part for me... If you have a website it wouldn't be Windows, unless that webserver is running on Windows. It doesn't have anything to do with the client side operating system however. Also, are you attempting to send from an authenticated google email account of your own? Have you tried changing your Google account settings to "
Allow less secure apps: ON"? By default Google provides some restrictions on what devices and services can access and use their SMTP servers.
If you're sending an email from the hosted server, it would depend on the SMTP restrictions and configuration of that server, in which case it's always good to research if changes were made for your hosting.