Secure Mail Server Setup

I need a complete, production-ready mail system installed in a physically secure datacenter environment. The core requirement is end-to-end delivery over SSL/TLS so every connection—IMAP/POP, SMTP submission, and server-to-server relay—remains encrypted by default. I haven’t locked myself into a specific stack, so feel free to propose Postfix with Dovecot, or any other combination you trust; stability, security, and maintainability are what matter most.

• Mail services
– Install and configure the chosen SMTP and IMAP/POP services.
– Generate or obtain trusted SSL certificates (Let’s Encrypt is fine) and enforce TLS-only connections.

• DNS & delivery hygiene
– Create the required MX and A records.
– Advise on SPF, DKIM, and DMARC so I can decide whether to enable them in a follow-up step.

• Validation & hand-off
– Prove that messages send and receive securely from major providers (Gmail, Outlook, Yahoo, etc.).
– Supply clear documentation covering packages used, key config files, renewal commands for certificates, and routine maintenance steps.

I also need old email migrated from other mailservers to this new one.

The Email server must work flawlessly with desktop and mobile mail applications.

Once everything tests cleanly—no open relays, no certificate warnings, and mail reaches the inbox without landing in spam—the project is complete.