IMAIL stops sending AND other network wierdness

[dovmar]

HI,
I saw the post on 'Imail stops sending' and have tried the solutions offered, but I wanted to get a full hearing on this issue as it seems related but, well stranger!

The server will move along fine for a few days and then, in the middle of the transmission session, will begin to get 'MX connect fail' errors. This (according to ipswitch) means that the Imail smtp service has gone out to DNS, gotten the address of the recipient mail server, attempted to connect to it, and failed to initiate a session.

As time goes on, over thenext few hours, more and more of these failures occur.

Further, if you then go to a dos-box and try to telnet to the ip address port 25 (as a test), it fails to connect!

Now, these are mail servers for MCI, AOL, Hotmail, earthlink and so on, not just little guys like me with 50 or so domains.

What I am thinking is there is some memory leac, or protocol stack problem that after extended xmission, the nic or the driver just looses its mind.

Keep in mind also that not all of my transactions fail. Many work. But once this guy starts to fail, many more failures of the same type occur, and then I generally reboo the server, and it clears up. Till today.

Other info: server runs IIS 5, sqlserver 2000, coldfusion 6.1 (MX) and is a dell poweredge 1400SC dual cpu unit. I am not using the onboard NIC, I am using a 3com 3c905 series nic.

I am switching to a server class nic (compaq or HP/Intel or Broadcom) just in case, but has anyone necountered this idiosyncratic behavior with the telnet twist?

Thanks,

Marty Block
Kesem Technology, Silver Spring MD

 

[bcaff86]

I appaear to be having the same issue - did you ever figure this one out. When I reboot it will work fine for a few hours and then seemingly out of nowhere the errors come back.

Thanks for the help -

Brendan

 

[dovmar]

Brendan,
I saw a post someplace else, (I think) that talked about the necessity of turning OFF the web calendaring service IF you do not use it. So I went through services running on the bix and made sure that only the services I needed were running (as they relate to Imail).

I also turned off the caching in SMTP but left on the feature to skip servers with a 90 minute delay on retries. Why?

I surmeised that once we latched on to a SMTP server that was refusing our connections Imail was retrying to send to that very same server because it's IP address had been cached. So instead of going to DNS each time, it was going to cache, getting the same IP address, and failing. Couple this with a 20 minute retry and you get more and more and more failures. So by lengthening the retry time, and by forcing the server to go to DNS each time, I am getting more random connects to the big boys (they have lots of servers), and so I do not hit the same server who refused me over and over again. Further I spend more time rtrying to deliver new mail than resending old mail.

I do not know if it's 'solved' but I am getting much much better throughput and fewer 'duplicate' mx connect failures.

Marty