On Sun, 21 Sep 2003, Larry Smith wrote:
Both of these are perfectly valid responses. You get them at the same
time, or you get the second one sooner.
Not quite totally true. In the second case - it _will_ connect and initiate
the transfer (helo, mail from, rcpt to) phase of _sending_ the message. It
will fail, but it will make the attempt. Whereas with the first case it will
never try. The second is much, much slower from the perspective of a mail
Some may never try. Sendmail won't try in that case. But it is perfectly
valid to wait and try again. In such a case, the wait time is typical 3 to
In the second case, it takes usually about 300ms to setup a tcp
connection, and fail. This 300ms isn't too long to wait. I doubt that
most people would notice. Quite a lot of fuss over 300ms, I think.
And I am just thrilled to see IE not go to MSN when I type in a wrong
name. I've been showing this to everyone. Most people like the
demonstration, and trust Verisign more than Microsoft.