suspicious warning

When i go to upload a page on my website, i receieve the following warning i the preview window "This item is suspicious and has been blocked it. Images and links have been blocked fo ryour safety. If you think this mail item is not fraudulent, open it."
What i want to know is how it came to that conclusion.
What would cause the programme to say this?
If Smart FTP thinks the page is suspicious, then will the search engines think the same???!!

You can ignore the warning in the preview window. It only says that the preview window doesn't download the images for security reasons.