Kamal,
I seem to have put a stop to the downloading of most of them by setting up an email rule to delete,from the server,any email over 100KB in size.
When you've set up the rule click on it,to highlight it,then click on MOVE UP repeatedly to move it to the top of your list of rules.
Of course this rule will be of no use to you if you normally receive emails of this sort of size that you actually do want.
To set up the rule I did this.
I clicked on TOOLS/MESSAGE RULES/MAIL/NEW.
Then I clicked on the box,in Section 1,next to WHERE THE MESSAGE SIZE IS MORE THAN SIZE to select it.
Then I clicked on the underlined SIZE and typed in 100 and clicked OK.
Then I moved to Section 2 and clicked the box next to DELETE IT FROM THE SERVER,to select that option.
Then I clicked OK then OK,on the next page,to create the rule.
Then I clicked on that rule,to highlight it,then kept on clicking on MOVE UP until that rule was at the top of all my MESSAGE RULES.
Then I clicked on OK again and that was it all done.
John Clifford Hole [MVP] of Enfield Middlesex