I'm using IIS 6.0 for my sharepoint project, i had some problems with my application and wanted to view my IIS logs.
I have already enabled them from the general tab.
It should be inside C:\Windows\System32\LogFiles with the name folder SmtpSvc1, but the SmtpSvc1 it's not there, there are few other folders there like HTTPERR, Scm, SQM,SharePoint....
I believe by default the SMTP default service does not have any fields marked to log. I'm sure windows is smart enough not to write out the log file if you have not enabled any fields to be logged. View the attached screen shot