Q:

Can somebody explain these TIMEOUT entries in my IIS SMTP log?

For some mails I'm trying to send over our SMTP server I get entries in the log like shown below.
Can somebody explain WHAT is timing out here and what IIS is trying to do?
2011-11-27 13:57:26 10.177.121.40 OutboundConnectionCommand SMTPSVC1 BXWEB00 - 25 DATA - - 0 0 4 0 31 SMTP - - - -
2011-11-27 13:57:26 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 354+End+data+with+<CR><LF>.<CR><LF> 0 0 35 0 31 SMTP - - - -
2011-11-27 13:57:26 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 250+2.0.0+Ok:+queued+as+F35C24A057 0 0 34 0 31 SMTP - - - -
2011-11-27 13:57:26 10.177.121.40 OutboundConnectionCommand SMTPSVC1 BXWEB00 - 25 QUIT - - 0 0 4 0 31 SMTP - - - -
2011-11-27 13:57:26 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 221+2.0.0+Bye 0 0 13 0 31 SMTP - - - -
2011-11-27 13:58:32 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 TIMEOUT - BXWEB00.netfra.local 121 16777343 193 67831 637670 SMTP - - - -
2011-11-27 13:58:32 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 QUIT - BXWEB00.netfra.local 240 638122 193 67831 637670 SMTP - - - -
2011-11-27 13:59:57 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 EHLO - +BXWEB00.netfra.local 250 0 186 25 0 SMTP - - - -
2011-11-27 13:59:57 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 MAIL - +FROM:<Email-Service@serverdomain.com> 250 0 62 49 0 SMTP - - - -
2011-11-27 13:59:57 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 RCPT - +TO:<recipient1@anotherdomain.de> 250 0 35 32 0 SMTP - - - -
2011-11-27 13:59:57 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 DATA - +<CHILKAT-MID-937818f1-c530-c3c7-e380-cc106ff13646@BXWEB00.netfra.local> 250 0 155 67995 0 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 220+ffm2mta20.hpuss.de+ESMTP 0 0 28 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionCommand SMTPSVC1 BXWEB00 - 25 EHLO - BXWEB00.netfra.local 0 0 4 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 250-ffm2mta20.hpuss.de 0 0 22 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionCommand SMTPSVC1 BXWEB00 - 25 MAIL - FROM:<Email-Service@serverdomain.com>+SIZE=68278 0 0 4 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 250+2.1.0+Ok 0 0 12 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionCommand SMTPSVC1 BXWEB00 - 25 RCPT - TO:<recipient1@anotherdomain.de> 0 0 4 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 250+2.1.5+Ok 0 0 12 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionCommand SMTPSVC1 BXWEB00 - 25 DATA - - 0 0 4 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 354+End+data+with+<CR><LF>.<CR><LF> 0 0 35 0 16 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 250+2.0.0+Ok:+queued+as+DB9C54A057 0 0 34 0 31 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionCommand SMTPSVC1 BXWEB00 - 25 QUIT - - 0 0 4 0 31 SMTP - - - -
2011-11-27 13:59:57 10.177.121.40 OutboundConnectionResponse SMTPSVC1 BXWEB00 - 25 - - 221+2.0.0+Bye 0 0 13 0 31 SMTP - - - -
2011-11-27 14:02:02 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 TIMEOUT - BXWEB00.netfra.local 121 16777343 193 8813 637093 SMTP - - - -
2011-11-27 14:02:02 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 QUIT - BXWEB00.netfra.local 240 637280 193 8813 637093 SMTP - - - -
2011-11-27 14:05:02 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 TIMEOUT - BXWEB00.netfra.local 121 16777343 193 68489 636140 SMTP - - - -
2011-11-27 14:05:02 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 QUIT - BXWEB00.netfra.local 240 636608 193 68489 636140 SMTP - - - -
2011-11-27 14:06:02 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 TIMEOUT - BXWEB00.netfra.local 121 16777343 193 8501 605751 SMTP - - - -
2011-11-27 14:06:02 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 QUIT - BXWEB00.netfra.local 240 605939 193 8501 605751 SMTP - - - -
2011-11-27 14:07:32 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 TIMEOUT - BXWEB00.netfra.local 121 16777343 193 8813 605377 SMTP - - - -
2011-11-27 14:07:32 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 QUIT - BXWEB00.netfra.local 240 605565 193 8813 605377 SMTP - - - -
2011-11-27 14:08:58 127.0.0.1 BXWEB00.netfra.local SMTPSVC1 BXWEB00 127.0.0.1 0 EHLO - +BXWEB00.netfra.local 250 0 186 25 0 SMTP - - - -

A:

The timeouts were caused by not actively closing the connection from the client to the SMTP server. The component used was Chilkat (http://www.chilkatsoft.com/refdoc/csMailManRef.html) and the manual states:
The mailman object automatically opens an SMTP connection (if necessary) whenever an email-sending method is called. The connection is kept open until explicitly closed by this method. Calling this method is entirely optional. The SMTP connection is also automatically closed when the mailman object is destructed. Thus, if an application calls SendEmail 10 times to send 10 emails, the 1st call will open the SMTP connection, while the subsequent 9 will send over the existing connection (unless a property such as username, login, hostname, etc. is changed, which would force the connection to become closed and re-established with the next mail-sending method call).
Note: This method sends a QUIT command to the SMTP server prior to closing the connection.
However, this seems to be a problem for some SMTP server. They want the connection to be closed after each mail.

