Honestly if you need something battle-tested right now, those are solid choices.

I built this because I had specific pain points - didn't want to set up Postgres or MySQL just for email metadata, wanted calendar and contacts baked in for a complete Google Workspace replacement, and wanted dead simple config that still does DKIM/SPF/DMARC properly.

Future roadmap includes SendGrid-style stuff - API for transactional emails, webhooks. But the core idea stays: good architecture, solve real pain points, keep it simple and fast.