[Bender]

Out of curiosity do you front-end SMTP with postfix to have many queues/MX entries and a battle hardened front-end or is Stalwart handling inbound connections directly? Im thinking of moving from Dovecot to Stalwart so family members have more modern features on my fallback domains about half of my domains do not use Fastmail. In multiple companies I had several Postfix inbound servers to keep the internet from touching Exchange directly and have multiple nodes for companies to quickly hand off to in multiple locations.

[matesz]

I just run single instance for now with RocksDB backend for internal / search and S3 for blobs - that is what made me think it’s so flexible.

Never hosted Postfix / Dovecot stack, in fact this is the first time I host emails, but from what I understand Stalwart is designed to handle inbound directly.

For very high throughput inbound you could check out KumaMTA - it was designed specifically for that, but I think Stalwart doesn’t have bottlenecks in it’s clustered topologies which would require it unless you are doing something crazy.

They have very good docs in general IMO, here are docs on how to cluster - https://stalw.art/docs/cluster/configuration