I'm finding that some external links to external sites are being directed to an intermediate page ( http://www.example.com/?URL=http://www.link-destination.com ) with the "To proceed to the URL you have requested, click the link below:" line, followed by the destination URL as a link.
The links I am finding this with are being set inside a text_area field which is itself inside a Grid field. The text_area itself has formatting buttons shown (bold, italic and link only). The channel itself is set to 'Allow only safe HTML' and it has "Automatically turn URLs and email addresses into links?" set to 'No' (so links are explicitly made using the formatting button on the text_area field).
Other external links do not show this redirection behaviour, but they are created either using an Expresso field type or by simply being hardcoded into the template. Internal links of course use the {path=""} tag and so do not show this behaviour either.
I'm at a loss as to how to stop the text_area links from routing themselves through the intermediate page. It's not going to please the client if users have to click twice, once as normal then again on this transitional page.
What determines whether EE performs this redirection routine, and how can I prevent it (and have the external links go directly to their destination)?