Free Google workspace is over, which alternative for custom domain email?

Question

As you probably know, free Google worspace will be over the first of july 2022. I use this service mostly for the custom domain email (and google calendar too) since more than a decade.

My domain name is hosted by www.bookmyname.com which propose a pop3 and imap to be able to receive email, but there is not smtp available.

My plan is to create a free gmail account and add an external email account. But how to be able to send email with my custom domain name?

Do you have plan for a secure free smtp server?

Thanks for your help

ps: If stackoverflow is not the good place to ask this kind of question, could you recommend another place?