RE: [IMail Forum] Smtp fails and spool keeps growing

[Tony Gray - Network Administrator]

FWIW,   I had similar results with Imail 6.06 (all latest 6x patches applied).  I found the problem was my DNS server(s), not in my Imail server.  Mail is VERY dns intensive (especially when throwing stuff like Declude in the mix, which requires extra DNS lookups for certain spam tests), if you don't have quality, stable, local DNS to look at - pretty soon the queue fills up and smtp stops responding (in my case it would actually slow the entire server to a crawl, where the only remedy was the dredded reset button).  Throw a wrench in the works like that in with the recent trends of dictionary attacks and increased spam traffic, and next thing you know the server just can't take it anymore.   Since you mention that you can't connect to any DNS servers, this would make me look at DNS REALLY closely.  - make sure you're on the latest versions of your DNS platform (http://www.isc.org/products/BIND/ is what I would highly recommend) - make sure you've entered valid DNS servers in the Imail Admin - Imail uses the servers specified here, not what is in the TCP/IP control panel - make sure you've applied proper ACL's on your DNS servers, so you're only doing recursive lookups for those local hosts that need it (and not everyone on the internet - stealing CPU/DNS cycles that your Imail server needs).   I chased my tail on Imail crashing for almost 6 months.  We were rebooting it once every other day (if not, it would end up locking up on it's own about every three days) and starting to look at other platforms out of frustration.  In an unrelated maintenance/upgrade, we changed out a few outdated DNS servers (and updated the settings in Imail admin to point to the two new IP's).  All of a sudden Imail server was ROCK SOLID - has gone over 6 months without an unscheduled reboot (have to reboot for things like critical updates, etc., but never for a freezeup).     Also, I run declude and have it pointed at two different servers than Imail, so basically the DNS load is spread between 4 seperate DNS servers. It has worked beautifully since.   - Tony  -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of RD Hoot Hunt Sent: Monday, September 23, 2002 2:21 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: RE: [IMail Forum] Smtp fails and spool keeps growing I have been having this problem since we switched to Imail 7, last June of 2002. Imail tech support can't help us, though we have tried everything they can think of. Reboot is the only solution. One note though, we find that when the smtp stops sending mail, we have 4000+ ports open. It seems to us that Imail doesn't give up the ports and so the smtp can't send mail because there are no open tcp/ip ports. Which is also why we can't connect (MX Fail) to any DNS servers. We are looking at other mail servers.   This happens to us about every other day or two.   . R.D. Hoot Hunt MCSE Network Administrator Chappell Studio / Marathon Foto 641-472-6892  Ext 299   When in doubt, Reboot !     -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Adam (Snowboard) Sent: Monday, September 23, 2002 12:51 PM To: [EMAIL PROTECTED] Subject: [IMail Forum] Smtp fails and spool keeps growing We have recently been having problems sending mail with our smtp server. At times it crashes and will not send mail. When this happens, we ussually have to restart the server for without the smtp service started, make a new empty spool directory, start the smtp service, and then start moving the files from the old spool over. I have a couple questions.   1) Is anyone else having the same problem. Smtp sevices craashes and spool directory builds while noe mail is sent and there is no warning given on the server.   2) What is the best way to solve this problem. Do we have to shut down the server to fix this, or is there another way to do it? We really don't like shutting down the server, but it seems like that is the only way to do it.