Secure Postfix Mailserver Setup

I need a Postfix-based mailserver configured so our team can reliably send and receive email. Security is paramount, so the build must include SMTP AUTH, TLS/SSL, and STARTTLS throughout. Mailboxes will be accessed over IMAP only; no POP3 is required. Here is what I expect: • Install and configure Postfix on a Linux host of my choosing. • Enable and verify SMTP AUTH, TLS/SSL, and STARTTLS for all connections. • Integrate an IMAP service (such as Dovecot) and align it with the Postfix user database. • Harden the server with sensible defaults—SPF, DKIM, basic rate-limiting, and anti-relay measures. • Provide concise documentation that shows key config files, how to add new domains/users, and how to back up the settings. I’ll supply root or sudo access to a fresh VPS and DNS records as needed. Once you’re done, I’ll run live tests; your work is complete when mail flows both directions securely and IMAP clients connect without certificate warnings.