thanks! got it working now. In SendGrip generated an api key, at - POSTFIX_smtp_sasl_password_maps=static:smtp_username:smtp_password
filled in apikey:[theapikey]
and relayhost=smtp.sendgrid.net:587
also add a verified From address in SendGrid, which is added in your lemmy.hjson email.smtp_from_address
after installing with ansible, change the docker-compose.yml file on you server passing the api in the ENV variable:
the postfix section now looks like this