Its not Sprint seven, Sprint's version (made by seven) allows for one non-html + no attachment push email. Its far more limited compared to the main one.
Seven's beta mobile mail app allows for HTML/attachments & more email accounts
You can get that one here...
http://community.seven.com/forum/main.php
BTW I had no luck getting it from the PDAphone(Mogul) so you
might wanna email the file to yourself. Texting it to myself did work either...