tl;dr; I would like to send emails using my domain extensions. I own some domains registered on Gandi, and I would like to send you an email using an email address using this domain extension.
Recently Gandi removed its free mailing service. From long ago, I have domains registered on Gandi + an email redirection to my Gmail address (in order to receive emails sent to [email protected]) + a [email protected] email account on Gandi (allowing me to send emails using my domain extension) + eventually a "Send mail as" rule on Gmail that uses the SMTP server of Gandi postmaster account. With this, I can receive emails from all my domains on my Gmail account, and I can select from Gmail from which email (domain) I would like to send my email.
Unfortunately, since the Gandi migration, I cannot use the free postmaster account anymore. Thus I cannot send emails from Gmail with my domain emails.
What option do I have to send emails as before, if possible signed and without headers from my gmail account?
I was thinking about getting a VM, modifying the DNS entry on my domains, installing a postfix server and trying to find a good tutorial, but I've read this from DigitalOcean:
As of June 22, 2022, DigitalOcean is blocking SMTP for all new accounts. As a part of this new policy, we have partnered with SendGrid so our customers can still send emails with ease.
Not sure what it means, and not sure how can I fix my issue.