Markus,
         Did you happen to alter any of the defaults for Imails SMTP settings 
(i.e. sessions, threads, etc.)?  You push as much email as we do per server, be 
interested in what you have your defaults at.  Thanks for the time.
 
Keith

        -----Original Message----- 
        From: [EMAIL PROTECTED] on behalf of Markus Gufler 
        Sent: Tue 3/1/2005 12:10 PM 
        To: [email protected] 
        Cc: 
        Subject: [IMail Forum] To anyone who bought a 3Com Nic
        
        

        Note: maybe this is not new for certain people on this list but as it 
was 
        not easy for me to resolve it, and also neither Ipswitch seems to know 
this. 
        So I want to tell you what happened me with our brand new server: 

        Our new Win2k3 Dell server with Dual Xeon CPU's, 2 Intel and 2 Broadcom 
        Nic's has had the problems that after a short time of higher smtp 
traffic 
        more and more connections failed. This problem was already described by 
        several people on this list, and Ipswitch's solution was to buy "a 
bether 
        NIC" (I must laugh again any time I hear it :-) 

        Well, the problem was here, the new machine seemed working poorer then 
our 
        previous "4 year old noname-assembled server" with realtek NICs. 

        It was a little bit of work to explain to other people in my company 
that we 
        need a "bether NIC", nobody has heard this before even if working for 
over 
        15 years in the hardware/server business. Ok new 3Com neek arrived, 
disabled 
        4 (four!) preconfigured Dell NICs and attached the 3Com card to the 
network. 

        Run the test again: gatewaying 1000 messages each one send with a delay 
of 
        300 ms trough the server. (more the 260000 msgs/day) 
        Surprise! The previously in hundreds appearing "MX CONNECT FAILED" and 
        "status=3"-lines in the logfiles has reduced down to around 30. 

        But successfull delivering 970 fom 1000 messages it not acceptable, 
even if 
        the missing 30 was requeued and delivered with the next queue run! 

        Searching the archives I've found Sanford Whiteman's post about TCP 
registry 
        settings: 
        http://www.mail-archive.com/[email protected]/msg94971.html 

        After changing this two values (TcpTimedWaitDelay: 60 seconds / 
MaxUserPort 
        = 25000 ports) there was not more one single "MX connect failed" or 
        "status=3" in the logfiles. All messages was delivered immediately. 

        Watching the "forgotten" TCP-connections left by Imail in WAIT-STATE 
with 
        "netstat -n 5" I've discovered that the connections from the random 
local 
        port to the remote port 25 remain in wait state for a to long time 
        (default=240 seconds) so that after reaching the default MaxUserPorts 
limit 
        of 5000 and beginning new from port 1 on each try to connect from an 
local 
        port already in WAIT-STATE will cause a MX CONNECT FAIL and so a 
requeueing 
        of this message. 

        So by reducing the TCPTimedWaitDelay down to 60 and increasing the 
        MaxUserPort there was enough time for the OS  to free up the forgotten 
        WAIT-STATE connections before the connection limit was reached and so 
there 
        is no more conflict and no more errors. (until the number of processed 
        messages in a short timerange will become high enough to catch the tail 
        again) 

        Now back to the subject of my post: Removed the 3Com re-enabled the 
Intel 
        Nic with the new registry settings suggested by Sanford: No errors even 
if 
        sending 400000 messages trough the server. It seems to me that the 
onboard 
        NIC of the DELL processor are even more performant then the 3Com nic 
but 
        that is not confirmed by a scientific test. 

        So please forward the bills of your 3Com NICs to Ipswitch, or maybe ask 
a 
        credit to buy ICS...  ;-) 

        Markus 


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