I have to say I am highly disappointed Windows Phone 8.1 still lacks of such a very basic feature.
Just yesterday I had to do some office work with just my phone available. Sending a mail with two photos, one PDF and one word document. I was frustrated by finding out the mail client only attaches photos. I tried office hub which works - but,only one document at a time. I used the rather new file manager released by Microsoft which then at least allows me to select multiple files within the same folder and attach them.
The next task was actually to receive an attached PDF, copy it via USB to a desktop computer and,print it. I honestly ended ended up not being able to do that. I viewed the PDF earlier on my phone with Adobe Reader, just to find out the file isn't stored anywhere where I could access it. I also wasn't able to save it afterwards.
In the end I actually used my BlackBerry where it was a one minute job before the first pages got out the printer. For me "little" things like this matters when it comes to usability. When I did a quick research yesterday I was surprised to see complains about such problems date back to 2010. Four years later and many OS updates later this still exists. Even though MS actually tries to aim their devices at businesses, I am wondering what kind of business wants phones without proper mail attachments.
After all thank you for the tip with Pocket File Manager, it actually worked. While this is nice, it still is no excuse or whatever for Microsoft to lean back and do nothing. Yesterday I was soooo close of just popping out my main SIM off my 1020 and put it back to my BlackBerry. Less apps, less entertaining OS but in terms of multitasking and efficiency it almost runs circles around the Lumia which is crippled,by weird MS design decisions.