Can not download PDF on iPhone 5s

So I just bought iPhone 5s last week. I get a lot of PDF documents and they downloaded just fine on my iPhone 4, but now that I've upgraded, the PDF documents just will not upload on my phone.

However when I go on my laptop and view that email, the attachment upload just fine on my phone.

In my phone it says downloading 0 bytes for 0 bytes, but on my computer it'll say the exact size of the file.

I am getting really frustrated because PDF documents are a thing I deal with on a daily basis.