Most email virus require to be executed through either of these methods:
The email software and/or the operating system automatically runs the file when it sees it. This is the case for pictures that exploit flaws in the picture-rendering libraries: the software processes the picture automatically (if only to show it as a thumbnail), triggering the exploit.
The gullible human user is induced into running the thing.
Most email virus follow the second path, since it is much easier. Flaws in software libraries are reported and patched by vendors; flaws in the human brain are never fixed. Typically, the file will be called ".zip.exe" (the user will just see ".zip" and think "this is a Zip archive, not an executable), or ".scr" (the user is not aware that "screensavers" are actually executable files in the Windows world). When the virus is of the second kind, downloading the file is safe, as long as you take care not to execute it. Beware of double-clicking it !
If you can arrange for a transfer without downloading it on your work machine, this would be safer. For instance, if you can access your emails through a Web portal, then do that from, say, a machine running Linux (could be a VM). As a rule, Windows virus don't impact Linux, and vice versa.