注册邮件发送服务https://app.brevo.com/
I use Brevo.com to use SMTP to send mails , which allow 300 mails per day for free.
One step is somehow complex is you need register your domain.
click on your company name in the top right corner of the screen, and select Domains.
then choose not let Brevo to manage DNS record,
and then manually add 3 txt recorders at your DNS recorder.
- Brevo code
- DKIM record
- DMARC record
Then wait some minutes and test and pass at Brevo.com , then you can use Brevo.com’s SMTP to send mails now.