Sendmail and Unexpected EOM

Scott Silva ssilva at
Mon Nov 5 15:52:30 GMT 2007

on 11/5/2007 4:33 AM Quentin Campbell spake the following:
>> -----Original Message-----
>> From: mailscanner-bounces at [mailto:mailscanner-
>> bounces at] On Behalf Of Scott Silva
>> Sent: 29 October 2007 17:55
>> To: mailscanner at
>> Subject: Sendmail and Unexpected EOM
>> I'm getting a lot of collect: premature EOM: unexpected close
>> errors from certain servers, and a google gives me much conflicting
>> info.
>> Running CentOS 4 and current stable MailScanner.
>>  I have tried decreasing the MTU on the external interface, and only
>> succeeded in stopping all traffic. Tried disabling window scaling, and
>> that also had no effect. Could the default be to set no-fragment on
> packets
>>from CentOS 4?
>> [snip]
> Scott
> What evidence do you have that it is your end rather than the sending
> site, or somewhere in between, that is at fault?
> Although a 'traceroute' does not always work (because ICMP is disabled
> at gateways) it may indicate some large delay on the route between the
> sender and you.
> I also see the 'premature EOM' messages here and have assumed them to be
> a problem for the sender, not us. 
> Where they occur after we have returned 'REJECT' status for all
> recipients after a DNSBL lookup, I assume that because the sender is a
> spammer they do not bother to close down the SMTP connection with a
> RESET or QUIT and simply move on to start a new SMTP connection with
> another target.
> Quentin   
I know that it isn't my end causing the problem, but the changes to linux and 
the receive window in the tcp stack has added to the errors.

MailScanner is like deodorant...
You hope everybody uses it, and
you notice quickly if they don't!!!!

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