On Thu, 18 Oct 2001, [ks_c_5601-1987] ���ȣ wrote: > Hello. > > How much enlarge CPU and Memory size of XMail Server System Per increasing Mail >User....?
It also depends on the concurrency level. You could have 100000 users that suck the same system resources of 1000 if these users rarely access the mail subsystem. Having an SMTP/POP3 server with concurrency of 10% is very high and this means that the average sessions ( SMTP and POP3 ) open are the 10% of the number of accounts. On Linux ( i don't know for NT coz, you know, i have not seen the sources :) ) i could say that each session needs about 32k of _virtual_ memory ( stack + socket buffers + app buffers + ... ). So if you've 100000 accounts with 10% of concurrency ( it's high ) you'll need about 320Mb of _virtual_ memory. With IMAP you should be able to see up to 90% of concurrency with a memory requirements of about 3Gb, threads/open-fds requirements of about 90000. Maybe this is the reason why, after 7 years of its specification, POP3 is still _largely_ the most user mailbox access protocol. > And, the limitation of Mail User of XMail ??? (NT platform/Linux..) I think that the main limit you're going to have is your network bandwidth more than XMail, at least if you don't have a 100Mbps link to the internet :) - Davide
