Topic: Hardware requirements for 20000 email users

[jarkor]

Hi everybody,

I'm using SME server since a few years, but I've never used it for more than 100/200 users.
I'm planning to move an existing domain to SME server now, only for email service with only one domain, and I don't know the hardware requirements for 20.000 users, aprox.

Anyone has a suggestions about this, or any way to calculate it? If someone has experience with a lower or higher quantity of users, will be helpful too.

I've take a look at the documentation but there's no suggested hw config for such user quantity.

Thanks in advance for your help,
Jarkor

[Boris]

For more that 200-300 users I would probably look for a dedicated e-mail only solution.
SME is a great universal server for the small business, where you need everything in one small box (file/print/e-mail/gateway/web/domain etc..).
Just to give you an idea of large enterprise scale e-mail deployment, we have about the same number of users at work. Our e-mail solution is MS Exchange 2007 farm (not my choice and don't throw bananas at me). It include about 20 servers (2x4 Xeons, 32GB RAM each) with large SAN for many terabytes of e-mail storage and Large Tape library for the backups. This doesn't include all the AD infrastructure servers and 4 e-mail antispam/antivirus appliances in-front of it. Also e-mail SMTP gateways and firewalls are separate. Our requirements include shared distributions lists, global access list, shared calendars and other features. If it was e-mail for Internet users only with lesser internal support it may be smaller, cheaper solution.
For the large scale deployments, recovery, redundancy and reliability has to be well designed. Performance is a big factor too.

[cactus]

If it is only for e-mail I am not sure if you really want to use SME Server as this system is geared towards being a small business server. It contains a lot of services that are not directly needed for a mailserver.

If you need to cater such amounts I think you are better of installing a dedicated server based on RHEL/CentOS and install and configure it yourself.

On top of that you provide a very limited amount of information on how busy those 20k users will be.

How much mail will they be sending? With attachments? Only internal or also outbound? Do you want to have virus scan and anti-spam measures as well.

[jarkor]

Ok people, thanks for your responses.

I understand the goal of SME, and their target bussiness........The idea was just to minimize the setup time, because if the hardware is enoguh to support it, why not to use it? Cactus is right about the unused services, anyway I can directly disable and don't use them.........
Anyway, I need to plan if it's not better to build a new server from scratch, with qmail or postfix and all the stuff.

About the traffic, I don't have an idea yet, because the domain I will migrate, it's hosted on a exchange server too and they doesn't have the 20000 users, just a few of them. Of course the accounts will use attachments, but will be initially very limited in size, will provide outbound service too, and virus and antispam can be avoided, but is better if they're there. I know there's a lot more of cpu time consumed if I enable antivirus and antispam....

Boris, thanks for the data about your servers farm, but I think that there's no comparision between a exchange and a linux email server.....I didn't have experience myself with exchange, but I know it's very resource consuming, afaik.

Thanks, and if you have any other ideas, they'll be very appreciated.

Regards,
Jarkor.