The "150-" was required, so test #2 was successful:
C: DATA
S: 354 Start mail input; end with <CRLF>.<CRLF>
S: 150-Please Wait
S: 250 Message accepted for delivery. (bytes: 2573)
C: QUIT
Outlook accepted the "150-" without any error and waited for the 250
response.
A 250- should have worked as well.
Tony Hansen
tony(_at_)att(_dot_)com