I do not know exactly whether this should be reported
as a bug or as a feature request. Since I try to think
positively I report it as a feature request :-)
When I use OpenSmtp.net to send mail over an IIS'
smtp server or over an exchange server, this works
within a few milliseconds. If the Smtp server is Postfix or
Qmail, it takes something between 4 and 5 seconds.
I was able to reproduce this behaviour in several
machines/environments. For each of the tests the client
and server machine were connected by at least a