"steve" wrote in message
...
It was thirdly that caught my attention. I have unselected my
outgoing scan
(McAfee) selection and I have success in sending attatchments.


That's because the anti-virus is causing a delay between your e-mail
client and the mail server. The e-mail client sends your message in
the DATA command it sends to the mail server. The mail server expects
to start getting that content within a short time after getting the
DATA command. However, your anti-virus program is interrogating that
e-mail traffic and delays when it gets delivered to the mail server.
Because you are sending HUGE e-mails, the delay is long enough to
cause the mail server to timeout.

However, a timeout at the mail server DOES result in an error message
but you said there was no such error message. Did you look in the
Progress dialog window for the status to check for errors or were you
expecting some popup to appear?