Facebook detecting unsafe links means that Facebook is not sure that your link is safe to follow. If you notice that your content isn't reaching Facebook, a good place to look to troubleshoot the issue is in your feed retrieval log and on the Destination page within your admin. Here you see possible reasons why we couldn't retrieve and/or post your content to Facebook.
One such error you may see in the Facebook Account Notices on the Destinations page is:
"The content you're trying to share includes a link that our security systems detected to be unsafe: http://NAME_OF_SITE.com. Please remove this link to continue."
Unfortunately, this error is being returned by Facebook with no additional information to dlvr.it. dlvr.it does not know why they have decided that your URLs are unsafe, and we're unable to help clear the problem. You will need to contact Facebook's support to try to identify the cause and reach a resolution.