1st: in MS Outlook.
Tools > Options > mail Setup tab > click on Send/Receive button. by default "All Account" is selected, so click on Edit. there is an option says: "Download only heards for items larger than:" here u can specify the limit of the email size u are receiving .. for example, a 600kb email has been sent to u, and u enable this option and specify 500kb, u'll only receive the headers but no attachements.
2nd: in MS Outlook.
Create a personal folder, if u don't know how, follow these steps..
1) File > New > Outlook data file...
2) choose Office outlook data file.. or so..
3) choose where u want to save it. of course there should be a space in ur harddisk.
4) click ok to accept the settings.
5) right-click the folder u just created, and click on New Folder, name it Incoming.
that's it we are done here.
now to the next part.
Tools > Rules wizard or Rules and Alerts. "differs in each version"
Click on New Rule, select "Start from a blank rule". and click on "Check messages when they arrive", Next > Next > put a tick mark on "Move it to the specified folder". bottom window click on Specified and select the folder "Incoming".> Next > Next > Finish..
now what will happen, when someone sends u an email with an attachment of 5MB, it will be directed to ur Personal Folder, so it will not be in ur ISP's mailbox. so, ur ISP mailbox will act as a redirector, and it will always be empty. and u'll be keeping ur emails safe in ur Personal Folder.
Regards,
Mahmood Alnasheet