Yeah, IIRC they don't support this feature for PO boxes, but I managed to accidentally get it for mine when I filed a change of address form.
I use this with my PO box just fine. The problem is that the pictures are taken at the sorting center not at your local post office. So when things get really busy you'll get the picture a day or two before the letter ends up in your box.
I use this with my PO box just fine. The problem is that the pictures are taken at the sorting center not at your local post office. So when things get really busy you'll get the picture a day or two before the letter ends up in your box.