I am dealing with an irritating problem of customers getting disconnected from the mail server during a download of a large mail attachment using a POP3 client. I'm running Imail 5.04 on WinNT 4 SP5 on a Pentium II 333 with 128MB RAM. I found the following article on the kb at: http://support.ipswitch.com/kb/IM-19980119-DD02.htm Question/Problem: How many concurrent connections can IMail Server have? Answer/Solution: Somewhere around 500 concurrent on POP3, 400 concurrent on IMAP4. 1000 concurrent on inbound SMTP connections, 500 concurrent on Web Messaging. These are approximate and are based on a Pentium 200 with 64 mb of memory, 256 mb of swap space and 1 gb free disk space, NT 4.0 server, no other apps running, one test at a time. There are no actual programmed limits (except in Web Messaging @ 500) and are dependent on lots of variables. We did write a test app a long time ago and can far exceed the numbers specified above but performance degrades around the numbers given. The nature of POP3 (in normal delete mode) and IMAP4 (in normal disconnected mode) allow a considerably higher number of "apparent" concurrent users. The numbers above are for actual concurrent connections. Real use would provide "apparent" numbers higher than above (except web messaging). We have only about 3,500 users on our server, could this be my problem? Is there any way to monitor how many concurrent POP3 sessions are active? ________________________________ Justin Ellison [EMAIL PROTECTED] Internet USA, LLC 234-6413 800-603-3502 http://nebi.com
