Free email relay service

Here are some free email relay services that you can use:

  1. Mailgun: Mailgun offers a free plan that allows you to send up to 10,000 emails per month. You can use their API or SMTP relay to send emails.
  2. Sendgrid: Sendgrid offers a free plan that allows you to send up to 100 emails per day. You can use their API or SMTP relay to send emails.
  3. Mailjet: Mailjet offers a free plan that allows you to send up to 6,000 emails per month. You can use their API or SMTP relay to send emails.
  4. Amazon SES: Amazon SES is a free email service offered by Amazon Web Services. You can use it to send and receive emails, and it integrates well with other AWS services.
  5. OpenSMTPD: OpenSMTPD is an open-source email relay service that you can use to send and receive emails. It's free and open-source, but you'll need to set it up yourself.
  6. Postmark: Postmark offers a free plan that allows you to send up to 100 emails per day. You can use their API or SMTP relay to send emails.
  7. Mailgun's Free Plan: Mailgun offers a free plan that allows you to send up to 10,000 emails per month. You can use their API or SMTP relay to send emails.
  8. Sendinblue: Sendinblue offers a free plan that allows you to send up to 300 emails per day. You can use their API or SMTP relay to send emails.
  9. Yandex Mail: Yandex Mail offers a free email service that allows you to send and receive emails. You can use their SMTP relay to send emails.
  10. Gmail's SMTP Relay: Gmail offers a free SMTP relay service that allows you to send emails using your Gmail account. You can use it to send emails up to 500 recipients per day.

Please note that some of these services may have limitations or restrictions on their free plans, such as daily email limits or requirements to display their ads in your emails. Be sure to review the terms and conditions of each service before using them.