Is the Google GMail client able to download attachments for arbitrary file types? I emailed myself an epub the other day and went to the GMail app (v 2.3.5) on my android phone to download it.

While it showed me the attachment, I could not figure out how to download it. The email shows a pretty paperclip icon next to it, and at the bottom of email I get another pretty icon with a paperclip. But I cannot click(/press) on it. There is no preview/download button. The menu has no option to download it.

So my question is, is it actually possible?

I've seen a fair bit on forums suggesting it is not, but those are fairly dated threads. It seems somewhat inconceivable to me that one would not be able to download an attachment - as one person has put it, this seems like a feature shortcoming that is bordering on a bug.

An example of what I see is:
http://imageshack.us/photo/my-images/703/attachwhat.png/

My phone: Samsung Galaxy S 2 running VillainRom 2.4.2, Gmail 2.3.5, email sent from Thunderbird 3.1.14 on Windows 7.
As far as I know this was a new addition to the app recently, so it's surprising that it doesn't work for you.  I just tried emailing myself a .epub file and it worked just fine, I had a Download button to the right of the paperclip icon and attachment name.

I know that the Browser on many devices won't let you download any files that don't have a handler registered for their extension; perhaps this is related.  You can solve that issue via an app that registers for all files, such as Download Crutch; perhaps it will solve your attachment issues as well.  I'd reboot after installing it.  I have Download Crutch installed and have had no problems with it.