Virtualmin down by overworking

I have a small server which basically use mail server with 200-300 accounts configured on a new SATA disk, with 3 GB of RAM and a quad core, has been running fine for years, but it takes a few weeks with downtime almost daily from 5 to 15 minutes, I noticed that in the “normal service” is around 170-180 runtime process and 15-30 emails received per minute, but I have peaks of 400 emails received by minute and open processes duplicated 400 and that’s when I have the service drop until queues are generated and delivered to and returns to normal
I’ve been searching for logs but can not find the user / email account that gives me 400 emails at once, on one hand I would like to discover the source of the problem and on the other SMTP entry limit many emails at the same time, I tried to modify these parameters unsuccessfully, i appreciate some example


i dont think this is particularly a virtualmin problem. this to me sounds more like a load issue on your server.

you’ll need to monitor the server more closely to see exactly what is happening. system logs like maillog will let you know what is going on with flow of emails, and tools like “top” will give you an idea of system load averages, free memory, swap space used etc. if you are running any sort of services like “mailscanner” then you can expect resource overheads if you’re running between 15-30 emails every 60 seconds. personally, i think your server hardware needs to be upgraded to keep up…and you need to look into setting up things like policyd to manage overall traffic on your MTA.

Yes i think too it’s a load issue on my server, the question it’s how can i see the origin of this anormally sent mails and how can i configure my smtp to receive only 200 mails every minute for example ???

Thanks a lot