If the message is that it timed out, check with your ISP to find out if they are having problems getting the email to you via OE since they appear to be OK with not rejecting it due to the size of the file itself and allowing it to get to their web-based email spot.
Something you can check ahead of time in the IE (not OE) settings (Tools/Options) is the connection tab, then check in the modem settings to make sure it's not set for "disconnect if idle for XXX minutes"....if so, crank up the time to 60 minutes or take out the check mark completely and see if that fixes it.
Whenever I receive a large attachment (1-2+ megs), Outlook express I get an error message stating that my SMTP account has timed out. As long as the large attachment trys to come in, it blocks all other mail. The only way I can clear it is to go directly to my server mail account (comcast.net) where I can download or view the large attachment. After deleting it there, Outlook Express operates normally again. Is there some setting in Outlook Express that would correct this problem?