Network email issue
Hi guys,
I've got an odd issue here at work and was looking for some input/thoughts. We have an HVAC system that emails monitoring alerts to several of us. The issue is that these alerts are varied in arrival times, meaning some are on time, others show up anywhere from 2-25 hours after the alert was issued, often times in batches. The HVAC server is a simple Server 2003 box that sends smtp messages to a relay, which sends them to Exchange. (as an example, the boiler had issues last night, which caused a roof vent to get stuck open, which caused the secondary water pump to kick on...etc. All told, there were 7 alerts generated for this, all within 15 minutes, starting at about 8:55 pm. I received all of these alerts at the same time, 4:01 am)
The whole path of the emails (verified by the header) is HVAC-> Relay-> Spam Filter (baracuda)-> Exchange
The loss of time occurs somewhere between the HVAC issuing the alert, and the relay receiving them. Sometimes it's milliseconds, most of the time though it's hours. Any idea what would cause this? I'm not sure where to look, or what to look for at this point. We've ruled out the HVAC server and everything after the relay, which means it's somewhere in between. But there's nothing but network in between them...2 routers and 3 switches away. No other traffic has this problem.
Could Energy Efficient Ethernet switchports be causing latency like this?
Thanks!!
I've got an odd issue here at work and was looking for some input/thoughts. We have an HVAC system that emails monitoring alerts to several of us. The issue is that these alerts are varied in arrival times, meaning some are on time, others show up anywhere from 2-25 hours after the alert was issued, often times in batches. The HVAC server is a simple Server 2003 box that sends smtp messages to a relay, which sends them to Exchange. (as an example, the boiler had issues last night, which caused a roof vent to get stuck open, which caused the secondary water pump to kick on...etc. All told, there were 7 alerts generated for this, all within 15 minutes, starting at about 8:55 pm. I received all of these alerts at the same time, 4:01 am)
The whole path of the emails (verified by the header) is HVAC-> Relay-> Spam Filter (baracuda)-> Exchange
The loss of time occurs somewhere between the HVAC issuing the alert, and the relay receiving them. Sometimes it's milliseconds, most of the time though it's hours. Any idea what would cause this? I'm not sure where to look, or what to look for at this point. We've ruled out the HVAC server and everything after the relay, which means it's somewhere in between. But there's nothing but network in between them...2 routers and 3 switches away. No other traffic has this problem.
Could Energy Efficient Ethernet switchports be causing latency like this?
Thanks!!
Comments
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Everyone
Member Posts: 1,661
Simple test...
Logon to your HVAC server, open a command prompt, telnet to the relay on port 25. Issue SMTP commands like the following
helo yourdomain.com
mail from:test@yourdomain.com
rcpt to:you@yourdomain.com
data
test
.
quit
Monitor queues on your spam filter and Exchange server.
You can repeat this going directly from HVAC to Spam Filter, and directly from HVAC to Exchange, depending on what restrictions are in place on those. It should help narrow it down.
The other thing you may want to look at is how the HVAC software generates messages, it may be creating the message but not passing them off to the next hop right away. The config for it where you enter the SMTP info may have some sort of "test" button.