For WooCommerce and form plugins, the MailBreeze WordPress plugin also syncs contacts and orders into MailBreeze. It is separate from SMTP and the two work together.
sasl_passwd holds your API key in plain text. Restrict it to root and remember it exists when rotating keys — a revoked key causes Postfix to defer mail quietly rather than raise a visible error.
Change the host, username, and password. Everything else in your existing configuration stays as it is. If you are moving from a provider whose SMTP host you reached on port 2525, MailBreeze accepts 2525 too, so the port does not need to change either.Your sending domain must be verified with MailBreeze first — DNS records from your previous provider do not carry over.