"
If you provide information on weapons of mass destruction or you take steps to hamper their use, we will do what is necessary to protect you and protect your families
"
E-mail message
Washington launched its e-mail offensive last week as part of its "psychological warfare" against Baghdad.
Government employees, senior civil servants, academics and scientists who use the state e-mail service are all thought to have received the letters.
The US has also dropped anti-Saddam leaflets from planes and broadcast messages against him.
One US e-mail told recipients: "If you provide information on weapons of mass destruction or you take steps to hamper their use, we will do what is necessary to protect you and protect your families.
"Failing to do so will lead to grave personal consequences."
Experts say that the fact that foreign e-mail servers are banned in Iraq would have made the campaign much easier as all recipients receive their mail on the same provider.
From Taleban to Saddam
The mass e-mailing adds a fresh dimension to an operation which began late last year as the US started trying to persuade Iraqis to abandon their leader.
Broadcasts transmitted by US planes flying over Iraq play Arabic music as a background to accusations that Saddam Hussein diverted revenue from oil sales to purchase arms instead of food.
"How much longer will this corrupt rule be allowed to exploit and oppress the Iraqi people?" one broadcast asks.
The "Commando Solo" plane which broadcasts the messages is operated by a specialist US psy-ops unit which was last deployed in Afghanistan when it broadcast propaganda to locals and Taleban fighters.
The US also uses ground transmitters in Kuwait and elsewhere in the Gulf to beam anti-Saddam programmes to the Iraqi people.