Outlook will not send any email with an attachment

[Peter Herijgers]

Hi All,

All of the sudden I cannot send any email with an attachment.
Sending an email without an attachment is no problem.

The email with the attachment isn't that big, only 2 kb.
Sending the email, the progress bar will stick at 50%.
If I am lucking I am getting an error message like 0x800040601.
But it's not enough to get into the problem.

The emails just stay in the outbox.

Any idea what is going on?
I have Microsoft OneCare as Virusscanner.

Thanks in advance.

Peter.