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Serge,
In both cases, SpamFilter is disconnecting the connection exactly 60 seconds after receiving the RCPT TO and DATA command:
08/21/04 01:18:50:000 -- (1496) RCPT TO: mailto:aaaa@zzzz" CLASS="ASPForums" TITLE="WARNING: URL created by poster. - aaaa@zzzz accepted
08/21/04 01:19:50:328 -- (1496) Disconnect
and
08/24/04 01:01:28:375 -- (1864) RCPT TO: mailto:bbbb@zqqqqq" CLASS="ASPForums" TITLE="WARNING: URL created by poster. - bbbb@zqqqqq accepted
08/24/04 01:02:28:687 -- (1864) Disconnect
Here's what we think is happening, but we need your confirmation to be more certain.
SpamFilter accepts the connection, and runs most of its IP-based tests to check it for spam. The remote server then sends the email's content, but SpamFilter does not see the traffic since "something" else is temporarily holding it. Once that "something" has done its job, the SMTP traffic is fofrwarded to SpamFilter. What is happening is that SpamFilter has a built-in timer to fight Denial of Service attacks. If it sees an incoming connection that does not transmit any data for 60 seconds, it disconnects it.
The "something" could be a firewall and/or a virus checking software that wait for the whole email body to be received, scan it for harmful content, and if clean, pass it on to SpamFilter. The problem is that if the email is large, or if the remote server is on a slow connection, it may take the email more that 60 seconds to be received by the "something". Once it is received, SpamFilter will have already cut the connection, thus the failure occurs.
If you're not able to change your network topology to solve this problem, the good news is that the timeout value SpamFilter uses is configurable via an option in the SpamFilter.ini file from version 2.0.1.358:
// New to VersionNumber = '2.0.1.358';
{TODO -cNew : Added ReadTimeout ini parameter to allow user control of timeout when waiting for remote SMTP commands}
In your SpamFilter.ini file, look for the follwoing line under the [server settings] section (or add it if it's not there):
ReadTimeout=60
You can change the number of seconds to a higher value, 300-600 should suffice in most cases.
Please let us know if this solves the problem,
Roberto F.
LogSat Software
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