Brevo transactional emails and DNS setup.

After email discussions spanning a few days, I set up google workspace accounts and added a couple of subdomains to google workspace - Brevo's setup includes CNAMEs for DMARC and DKIM records in the format subdomain1.ourdomain.org is a cname for b2.vsubdomain1-ourdomain-org.dkim.brevo.com and so on. 

So, set up email1@subdomain1.ourdomain.org as an alias for email1@ourdomain.org and so on, pointing the MX records to google workspace, so that bounce messages would be able to go somewhere. The reason I'm just not creating email ids like email1@subdomain1.ourdomain.org without aliases is because Brevo uses DMARC (a method of email server authentication) which would cause emails sent from google's servers to be marked as spam if we set Brevo to send authenticated emails from those email ids.

There were lots of back-and-forth emails saying emails are not being delivered. Finally, the dev team set up the domain authentication once again (which they had not done for subdomain2.ourdomain.org), sent me the details of the cnames & txt records to be added, I added them, and then all was OK.