We have done the increasing of the timeout value, to no avail. I access the mail server over the network, and have had no problems at all, but I get about 10-15 calls a day with dial up users having problems. Customers with 2 phone lines will do it when I'm on the phone with them, and the lights that blink in the systray just stop blinking when retreiving large attachments. If they open up a browser, the browser works fine. Am I looking at a problem with the mail server, or a possible problem with my switch? __________________________________ Justin Ellison System Administrator InternetUSA [EMAIL PROTECTED] http://nebi.com 800-603-3502 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of Daniel Donnelly > Sent: Tuesday, June 22, 1999 10:30 AM > To: [EMAIL PROTECTED] > Subject: Re: [IMail Forum] POP3 Concurrency limit problems??? > > > No, the number of user accounts is not your problem. > > I'd say that those clients that expect attachments should have the 'time > between POP3 checks' set to be greater than the time to download > all messages > and attachments. Many clients today come with this set to 1 > minute or shorter > and that is much shorter than necessary and WAY too often for > normal mail. Set > to 5, 10 or 15 minutes, depending on network connection speed (longer for > slower connections) and the time to transmit the attachment size > you expect. > If the user is dialup and expects 1Meg attachment, that could > take 10 or more > minutes, so set to 15 minutes between mail checks. On a local > network with the > same 1 meg, it could be 1 minute, but I'd still recommend it be set to at > least 5 minutes. There is no need to check a mailbox every minute or 2. > > Please note that this would, in effect, reduce the number of concurrent > connections, too. (users checks less often, so less checks are > being performed > overall and at any one time). > > If one telnets to POP3 server, there are some numbers at the end > of the '220' > line. The first shows number of connections since last restart > and the second > shows the number of current connections. Even in systems with > lots of users, > the second number usually ranges around 15-25. > > Daniel Donnelly > Ipswitch Technical Support > ________________________________________________________ > See our Knowledge Base at http://support.ipswitch.com/kb > URL for List Servers: http://www.ipswitch.com/Support/mailing-lists.html > > > In reply to 21 Jun message from [EMAIL PROTECTED]: > > >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 > > > > >
