> The exact source of the problem was a limit in threads in MS SMTP, > which is something like 20 per processor (not sure if hyperthreading > counts in this case). . .
This isn't an accurate claim. It sounds like you just haven't tried to tune MS SMTP appropriately for load/resources/growth. That's fine, since MS doesn't push you too hard on this, but please do some more lab work before deciding that MS SMTP is broken. Look into the following values: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\InetInfo\Parameters\PoolThreadLimit HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SMTPSVC\Queuing\MaxPercentPoolThreads HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SMTPSVC\Queuing\AdditionalPoolThreadsPerProc You also need to realize the differences between I/O completion port architecture, callbacks, and pure multithreading. It's possible to bottleneck anything, but that's an implementation problem with a given event sink, not a problem with the overall framework. > . . . this limitation in the MS SMTP architecture makes it > inappropriate for any full scale spam blocking solution such as > Declude unless you have that application ride behind MS SMTP instead > of being plugged into it. . . . Sorry, man, but that's FUD. I appreciate what you found with FTP in your config, but let's not jump over the available data. > One other note. I had previously used the Windows registry hack to > enable a native tarpitting feature in MS SMTP with even worse > affects. The built-in tarpitting in MS SMTP will delay all 5xx error > codes by the time that you set, and this included the 552 error used > when messages are over the maximum size. The result of this terrible > oversight is that a fair number of servers will not recognize the > delayed 552 error and will requeue the oversized messages over and > over again, and that eats up a lot of bandwidth real, real quick. Matt, you _know_ this isn't cause and effect, since you and I both looked at a specific server _without_ tarpitting enabled that exhibited the problem with oversize messages. There may be an additional wrinkle added by ttarpitting, but it's not the root cause of the problem. --Sandy ------------------------------------ Sanford Whiteman, Chief Technologist Broadleaf Systems, a division of Cypress Integrated Systems, Inc. e-mail: [EMAIL PROTECTED] SpamAssassin plugs into Declude! http://www.imprimia.com/products/software/freeutils/SPAMC32/download/release/ Defuse Dictionary Attacks: Turn Exchange or IMail mailboxes into IMail Aliases! http://www.imprimia.com/products/software/freeutils/exchange2aliases/download/release/ http://www.imprimia.com/products/software/freeutils/ldap2aliases/download/release/ --- [This E-mail was scanned for viruses by Declude EVA www.declude.com] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com.
