Documentation improvement points in multiple areas

[zamazan4ik]

Hi!

After reading the documentation I've noticed the lack of multiple important areas. I think I need to write my questions here, which are important to me and should be described in the documentation.

• Supported Hardware Architectures/OS combinations. From the Install page, it's not clear, which hardware architectures (like x86-64, ARM, etc.) are supported on which Operating systems. If you have special requirements for the instruction sets (like AVX) - write about this in the documentation too. Knowing it is important during the hardware planning phase (CAPEX calculations, etc.). Having ARM support is important for desktop users during the development phase (Macbook machines + some Lenovo ARM-based laptops) and servers (like AWS's Graviton, Google Axion, etc.). If you have different support levels for different hardware architectures - it will be great to know that too.
• How to install on Kubernetes? Is it supported by the project? If yes, please describe, how the mail server should be installed on k8s. It will be awesome to have something like an official Helm chart (or any other way to deploy on k8s). In many cases, Docker instructions are not sufficient enough in production-like environments.
• Are there any recommendations regarding setup on cloud environments (like AWS/Azure/GCP)? E.g. reference architectures, recommended hardware (e.g. recommended AWS EC2 machine type)? What about reference deploy architectures for on-premise installations? Having such references can make an administrator/devops life much simpler.
• What are currently the largest Stalwart Mail Server installations? I want to understand how well the solution scales in practice. Here there is a simple answer "yes, it works" but having more numbers can be valuable here since making data-driven decisions is a good thing to do ;)
• How could I install Highly-Available (HA) deployment? Are there any restrictions/recommendations regarding network latency between nodes? Since you claim about production usage I guess somewhere there are HA clusters :) It will be nice to read about such scenarios for a "serious" production. I expect here we should do something more than "use documentation for your storage".
• How to upgrade/downgrade the mail server? Does it support zero-downtime upgrade and downgrade procedures? What about compatibility between releases - what is the current policy?
• How to backup and restore Stalwart? Are there any built-in integrity checks for the backup? At least writing something like "Nothing special from our side - use corresponding backup\restore procedures for your backend" but in general we need to have a dedicated to the Stalwart documentation.
• How to monitor the mail server? Does it support any kind of integrated monitoring (like Prometheus endpoint, statsd integration, etc)? If yes, how can I configure it, and which metrics are supported? Is there a ready-to-use Grafana dashboard for Stalwart? I found the page about tracing and monitoring but found nothing about metrics.
• Not sure if should I create a dedicated issue for that or not. Is any kind of compression supported in the mail server? I found only this issue that was closed after LZ4 support. Are there plans to support other algorithms like Zstd?
• Probably there are other improvement points in different areas. Some ideas could be found in the Dovecot documentation. Possibly good things to document are stuff like performance tuning.

I think this list could be somehow transformed into the documentation task epic and could be resolved step by step.

[mdecimus]

Thanks for the suggestions! Will definitely take them into consideration as we move towards version 1.0.