Question of deploying mail-in-a-box for 800 users in AWS

Hi everyone. I am new to mail-in-a-box I have a couple of questions about deploying mail-in-a-box specifications in AWS

  1. if I have around 800 users, what kinds of CPU (t3.micro, etc) and RAM are required for smooth performance?
  2. I have multiple domain names for different groups of people. Is integrating and managing those domain names with one mail-in-a-box server possible?
    Thank you for your kind attention.

A lot depends on how much each user uses ie some users only have a 15MB mailbox other’s have 3GB or more. Get a total for all users * 2 .5 would be a rough guide to disk space required.

With regards to domains from what I see there’s no limit, if you use internal DNS on MIAB this will handle all of the settings.

Hope it helps

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If your users don’t use nextcloud 2GB RAM should be OK. If yes go for the 4GB. You can even use an arm64 instance only backup dosen’t work out of the box but there is a workaround.

Disk space is a problem and is expensive. There is a version with mailbox quotas on git which would help in terms of disk space. As for CPU any of AWS option is good. You must also fill the form to remove port 25 limitation.

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Define multiple … if more than 10 or so (definitely 20) then…

Here is the problem that you are likely to experience. Your status checks will always time out. Your mail users page likely will as well. You’re going to have to do everything via command line or API.

This is due to the nginx timeout on the admin pages. You may be able to tweak the settings if you are a programmer and understand the code.

Your next issue is storage space. AWS is expensive as hell. You will also find your server “down” for hours each week during the Sunday maintenance performing backups.

Honestly, I just wouldn’t do it.

I guess it depends on the server too?

I dont seem to have this problem…

1 of my servers is hosting 20 domains, with about 10 users per domain.

Everything works fine. I will say that I use a quota’s fork so mailbox sizes are small(er) with most users at 2G mailboxes and some at 5G mailboxes and 1 at 7G mailbox.

Status pages load fine, backups are fine, the box is pretty responsive.

I do host my own server (its virtualized) but the VM is decent sized. 4CPU 8G RAM 400G Disk (spinning disk)


800 Users might be a lot, but with the right size server not impossible, although I guess I’m doing about 200 users. which is 1/4.

Might want to consider - VPS with the Best Price-to-Performance Ratio | Contabo
Cloud VPS 4 or 5? I’d also take the SSD option over NVMe.