Thanks for getting this posted here, I believe our community would be happy to provide details on their results here. In the meantime, you can review our help documentation on high volume deployments as well: 

We run one of the largest SmarterMail installations that they support and the SmarterMail build we are running right now performs extremely well. CPU usage is basically nothing compared to some of our other systems, such as web servers, SQL Server etc. RAM usage We sit around the 15-20GB usage area, but we certainly do not mind increased RAM usage if it translates into better performance. Disk IO across our RAID10 array is also extremely low, it used to be an issue, but lately SmarterTools has done a really good job of optimizing SM to not be so hungry for resources.

We have 2 anti-spam gateways that run rspamd, they feed our primary SM Server incoming mail, we have a linux system that runs ZoneMTA that handles all the outgoing mail. One day, we hope to dump the ZoneMTA system, just waiting for the day SmarterMail supports and can do its own outgoing IP rotation.

Our system size is well over yours and we have no problems at all with SM performance.

The vast majority of our users are Outlook and Tbird based, running IMAP and POP3 + SMTP. We do have a good chunk that uses the web interface exclusively, and decent size number of users who use Exchange Web Services (eM Client and Apple Mail). Getting users to pay for access to their email for something like ActiveSync is a hard sale.

Hi echoDreamz

Can you please guide more on ZoneMTA, we are having IP rotation issue with SM and would like to know more about ZoneMTA and how does it work. Are you facing any issues with SM integration?

Hello,

We no longer run ZoneMTA, we used it for a few years, though it was quite CPU heavy, especially during newsletter blasts etc. We have since moved to postfix with their IP rotation and it works perfectly.

Thanks exhoDreamz

Let me give it a try, I also wanted to know how do you handle incoming spool, do you use SM default spool and have incoming gateway configured. Asking because I want emails to be in spool if SM server goes down and when the server is up it should deliver the email to the user. The emails should be in spool for 2-3 days.

Ashish,

We have 2 incoming gateways running Postfix + rSpamD + some custom stuff. Yes, if our main SM goes down, our incoming gateways still continue handling incoming mail and holding it.

Thaks echoDreamz 

I did manage to configure postfix with IP rotation, but have few roadblocks

1) How can I rotate IP based on number of emails sent per IP, currently they are rotating randomly 

2) Postfix does not connect to Sm via authentication, do you have any idea how can I achieve that?