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.
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