Postfix version 3.7 is still up. When will we upgrade it to higher versions? I'm trying to use IPv6. I want to use allow_srv_lookup_fallback, but I can't test it because IPv6 doesn't have 3.7.
debian trixie has 3.10[1], which should include what you're looking for. We mostly just take the versions debian ships, and for bookworm that was 3.7[2]. Our PVE 9 beta[3] is trixie based, so either wait still stable, or try the beta. Alternatively just adding the trixie debian repos should also work.
Q: When do you expect the stable Proxmox VE 9.0 release?
A: The final Proxmox VE 9.0 will be available as soon as all Proxmox VE 9.0 release critical bugs are fixed, and new features are deemed stable.