If you are using an email address the service will stop soon as the Google service is ending, see here.

If you would like to backup your emails one way is to turn the IMAP on in settings and use something like thunderbird portable to download everything to your computer/usb.
The actual timeline may move but having backups done before May would be smart. I am not sure if Google has or will contact you directly.

It was a lot of fun.
Thank you,
Rusty / John