According to this article there is a free smtp sending option of up to 500 e-mails a day:
https://www.cubebackup.com/blog/how-to-use-google-smtp-service-to-send-emails-for-free/
**Prerequisites and limitations
To use Google’s SMTP service, you need to have either:
1. A free Gmail account, like someone @gmail.com, which allows you to send up to 500 emails per day.
2. A paid Google Workspace account, like someone @mycompany.com. Google Workspace accounts can send up to 2,000 messages per day.
Haven’t used gmail for smtp sending myself and not certain this is all accurate information at that page.