email virus? help!

Hi,

On two occassions over the past few weeks, I have received an email claiming to be returned to me because the recipients account is over quota.

Strangely, I am not aware that I sent this email in the first place... and there is nothing untoward in my "Sent Items" folder.

Can someone else be sending out emails under the name of my account?

Is there a prospect of my computer being seriously affected?

Every now and then my screen blips, and the internet monitor shows activity, but I am not doing anything other than typing a message to HC.

What's going on?

Help! Pls

GK