I want to use SendGrid as my email sending service, but want to also use Postfix's internal queue mechanism to manage the emails sent through Sendgrid.
So basically what I want to do is to configure Postfix to send emails through Sendgrid's SMTP, and I will configure my app to send the emails using the local Postfix.
My question is, how can I configure Postfix to use an external SMTP? Looked here but didn't see anything useful.
Best Answer
This is detailed in http://www.postfix.org/BASIC_CONFIGURATION_README.html#relayhost