You do not have a hacking problem. What you see there is a result of someone who has your email address on their computer and that computer has a virus. (or is part of a bot-net)
The virus has its own email engine, which makes it independent of the users own mail carrier, and goes around the infected PC looking for email addresses. They are all over the place on a computer. It collects them all up, composes an email, sometimes a replica of the virus and sometimes just Spam, and selects one of the addresses that it found as the From address.
In your case, you were the lucky contestant. Obviously not all the email addresses were valid which triggers the far end email server to send an "unable to deliver" message to the Sender. As your address was chosen as the From address, guess who gets the bounce messages.
Bottom line, No Hacker.
The toolbar "problem". Reboot the Mac and go back into Mail. Now try Customizing the toolbar again. Dragging any of the icons off the toolbar and into the Customize window will cause that icon to vanish in a 'poof"
Relax, no problems.
By the way, did know that there is a whole set of Mac forums here on CNET where you will get a much faster response to any Mac problems that you have.
You will find them at http://forums.cnet.com/mac-forums/?tag=TOCleftColumn.0;blankArea.5
See you over there
I just received an email from the Mailer Daemon (I use macmail & PacBell/Yahoo.com ) saying that the email I sent to 7 addressees was undeliverable to two of them. The text was "How to turn successful from home" with a link after it. I did NOT send this email. The two emails that were undeliverable were to people that I know but are not in my address book or emails files. Two that were delivered are also not in my address book or email files. The other 3 emails that were delivered are to contacts that are in my address book. How did this happen?? I also just noticed that on my mail toolbar, the icon for delete has been changed to "undelete" When I click on the toolbar to customize it- I can't drag any of the icons ( "delete" specifically,or any others ) to the toolbar. When I clicked on the "undelete" icon then- it disappeared in a "poof". Do I have 2 separate problems just coincidentally occurring at the same time?? What is the cure??