[VOPmail Beta] SMTP failure

[Robert Sinclair]

Title: Message

Ah, OK, another thing that I have experienced when this happens.   1. Check the number of current connections, you can use the performance monitor, but I also use netstat because it shows stagnant connections as well.  If you have a whole lot of connections on the box (my all time record was nearly 2000) It has been my experience that the smtp service does not respond. It is most likely due to limited resorces on the TCP IP protocol because I have plenty of memory and my CPU is ok as well.   To combat this I wrote a small exe that looks at the netstat and counts the number of connections per IP address, then if a threashold is met (I select 3) it puts the IP address in a text file that I merge with the one that VOP mail uses to block IP addresses. Works great, but I have to run it every 5 minutes so for 5 minutes they can flood me. It helps with spammers too, becuase spammers have no regard, they want to blast as much email as possible, so they will open as many connections as they can.   2. If there is any slowdown to the SQL server that is servicing the VOP mail server. This is also been bad for us because I do error logging to the SQL server, so it can get bogged down. If it gets too bogged down or the database needs to be rebuilt VOP will sometimes studder waiting for it.   That's a couple more of my experiences.   ----- Original Message ----- From: Matthew J. Schwartz To: [EMAIL PROTECTED] Sent: Thursday, September 18, 2003 8:17 PM Subject: [VOPmail Beta] SMTP failure Grapevine,   Thanks for the response to Jaeme's posting earlier today.  We do quota maximum message sizes on all of our accounts, so I don't think we are getting any really large e-mails going through.    Just to clarify the problem we are having:   We are getting numerous complaints that our e-mail users cannot send outgoing mail and are experiencing timeouts when trying to send.  They can receive mail just fine.  We have looked into numerous possibilities each time this occurs:   - We checked our overall bandwidth to make sure we weren't max'd and we were at about 5% utilization of our bandwidth overall, so that wasn't the problem. - We checked the processor and memory utilization on the mail server, and both of those were barely being utilized. - We checked incoming and outgoing bandwidth on the mail server itself, and both of those seemed minimal. - We checked all VOP related services and all were running.   Looking at the environment, everything seems to be running fine, yet everybody receives timeouts when trying to send outgoing mail.  Up until about a week ago, we've been running VOP Mail for a long time without any problems.   Rebooting the server resolves the problem for some time and eventually it pops back up.  Any ideas are greatly appreciated.   Thanks! Sincerely, Matt Schwartz   -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Grapevine Staff Sent: Thursday, September 18, 2003 2:56 PM To: [EMAIL PROTECTED] Subject: [VOPmail Beta] SMTP failure I have had this problem in the past with LARGE emails, VOP mail takes an email and stores it in memory before writing it to disk (as explained to me, as I understood it.)   So when somebody sent a huge attachment, which we didn't have limits on then, it would slow down the whole server as it was being delivered. If it was really large, then NT would go to swap and that was the end of any response.     ----- Original Message ----- From: Jaeme Adams To: [EMAIL PROTECTED] Sent: Thursday, September 18, 2003 12:34 PM Subject: [VOPmail Beta] SMTP failure I was wondering if anyone else has encountered this before.  In the last three days our SMTP server has been dieing.  After a reboot it works fine for 4-5 hours and dies again.    VOP mail 5.1 Win Advanced server   Thanks Jaeme